CLIR

SEC source: 0001104659-25-016631 · tm257462-2_4seq1.xml · nonDerivative · entry 2

Hinds Brent · CIK 0001888082 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 112,929

F2 · shares: Represents the payment of the reporting person's tax liability by withholding shares incident to the receipt of the Company's common stock issued on February 20, 2025, based on the closing price of the Company's common stock on February 20, 2025, of $0.8588.

SEC source: 0001104659-25-016631 · tm257462-2_4seq1.xml · nonDerivative · entry 1

Hinds Brent · CIK 0001888082 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 131,686

F1 · shares: Represents a one-time bonus grant to the reporting person for services as an executive officer for the year ended December 31, 2024. The number of shares awarded is based on the closing price of the Company's common stock on February 20, 2025, of $0.8588.

SEC source: 0001104659-25-016630 · tm257462-1_4seq1.xml · nonDerivative · entry 2

Deller Colin James · CIK 0001766480 · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 171,853

F2 · shares: Represents the payment of the reporting person's tax liability by withholding shares incident to the receipt of the Company's common stock issued on February 20, 2025, based on the closing price of the Company's common stock on February 20, 2025, of $0.8588.

SEC source: 0001104659-25-016630 · tm257462-1_4seq1.xml · nonDerivative · entry 1

Deller Colin James · CIK 0001766480 · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 221,699

F1 · shares: Represents a one-time bonus grant to reporting person for services as an executive officer for the year ended December 31, 2024. The number of shares awarded is based on the closing price of the Company's common stock on February 20, 2025, of $0.8588.

SEC source: 0001104659-25-016240 · tm257346-1_4seq1.xml · derivative · entry 6

Hinds Brent · CIK 0001888082 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 10,127

Underlying: Common Stock · 10,127 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F7 · derivative.exercise_price: On February 2, 2023, the reporting person was granted a one-time bonus of 30,380 RSUs, and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F8 · derivative.exercise_date: The RSUs granted on February 2, 2023, vest in three equal annual installments that commenced on February 2, 2024.

F8 · derivative.expiration_date: The RSUs granted on February 2, 2023, vest in three equal annual installments that commenced on February 2, 2024.

SEC source: 0001104659-25-016240 · tm257346-1_4seq1.xml · nonDerivative · entry 4

Hinds Brent · CIK 0001888082 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 80,510

F4 · shares: Represents the payment of the reporting person's tax liability by withholding shares in connection with the vesting of 10,127 RSUs on February 2, 2025, and calculated based on the closing price of the Company's common stock, as reported on Nasdaq Stock Market, on February 2, 2025 of $1.20.

SEC source: 0001104659-25-016240 · tm257346-1_4seq1.xml · nonDerivative · entry 3

Hinds Brent · CIK 0001888082 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 84,222

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · shares: Reflects the vesting of 10,127 restricted stock units ("RSUs") out of the 30,380 RSUs granted to the reporting person on February 2, 2023, into an equal number of shares of the Company's common stock, without the payment of any consideration, pursuant to the 2021 Plan.

F3 · price: Reflects the vesting of 10,127 restricted stock units ("RSUs") out of the 30,380 RSUs granted to the reporting person on February 2, 2023, into an equal number of shares of the Company's common stock, without the payment of any consideration, pursuant to the 2021 Plan.

SEC source: 0001104659-25-001443 · tm252096-3_4seq1.xml · derivative · entry 1

Silva Gil Todd · CIK 0002028266 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 41,632

Underlying: Common Stock · 10,791 shares

Expires not disclosed

F1 · derivative.exercise_price: As compensation for services as a non-executive director during the quarter ending March 31, 2025, the reporting person was granted restricted stock units ("RSUs") under the ClearSign Technologies Corporation 2021 Equity Incentive Plan and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

F2 · derivative.expiration_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

SEC source: 0001104659-25-001441 · tm252096-1_4seq1.xml · derivative · entry 1

Maley David M · CIK 0002021245 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 72,263

Underlying: Common Stock · 13,219 shares

Expires not disclosed

F1 · derivative.exercise_price: As compensation for services as a non-executive director during the quarter ending March 31, 2025, the reporting person was granted restricted stock units ("RSUs") under the ClearSign Technologies Corporation 2021 Equity Incentive Plan and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

F2 · derivative.expiration_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

SEC source: 0001104659-25-001442 · tm252096-2_4seq1.xml · derivative · entry 1

Schrecker Judith S · CIK 0001850679 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 351,926

Underlying: Common Stock · 18,794 shares

Expires not disclosed

F1 · derivative.exercise_price: As compensation for services as a non-executive director during the quarter ending March 31, 2025, the reporting person was granted restricted stock units ("RSUs") under the ClearSign Technologies Corporation 2021 Equity Incentive Plan and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

F2 · derivative.expiration_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

SEC source: 0001104659-25-001444 · tm252096-4_4seq1.xml · derivative · entry 1

de Lacy Catharine · CIK 0001966673 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 161,925

Underlying: Common Stock · 13,848 shares

Expires not disclosed

F1 · derivative.exercise_price: As compensation for services as a non-executive director during the quarter ending March 31, 2025, the reporting person was granted restricted stock units ("RSUs") under the ClearSign Technologies Corporation 2021 Equity Incentive Plan and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

F2 · derivative.expiration_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

SEC source: 0001104659-24-105956 · tm2425553-4_4seq1.xml · derivative · entry 1

Silva Gil Todd · CIK 0002028266 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 30,841

Underlying: Common Stock · 18,477 shares

Expires not disclosed

F1 · derivative.exercise_price: As compensation for services as a non-executive director during the quarter ending December 31, 2024, the reporting person was granted restricted stock units ("RSUs") under the ClearSign Technologies Corporation 2021 Equity Incentive Plan and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

F2 · derivative.expiration_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

SEC source: 0001104659-24-105953 · tm2425553-2_4seq1.xml · derivative · entry 1

Maley David M · CIK 0002021245 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 59,044

Underlying: Common Stock · 22,634 shares

Expires not disclosed

F1 · derivative.exercise_price: As compensation for services as a non-executive director during the quarter ending December 31, 2024, the reporting person was granted restricted stock units ("RSUs") under the ClearSign Technologies Corporation 2021 Equity Incentive Plan and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

F2 · derivative.expiration_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

SEC source: 0001104659-24-105955 · tm2425553-3_4seq1.xml · derivative · entry 1

Schrecker Judith S · CIK 0001850679 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 333,132

Underlying: Common Stock · 32,181 shares

Expires not disclosed

F1 · derivative.exercise_price: As compensation for services as a non-executive director during the quarter ending December 31, 2024, the reporting person was granted restricted stock units ("RSUs") under the ClearSign Technologies Corporation 2021 Equity Incentive Plan and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

F2 · derivative.expiration_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

SEC source: 0001104659-24-105952 · tm2425553-1_4seq1.xml · derivative · entry 1

de Lacy Catharine · CIK 0001966673 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 148,077

Underlying: Common Stock · 23,712 shares

Expires not disclosed

F1 · derivative.exercise_price: As compensation for services as a non-executive director during the quarter ending December 31, 2024, the reporting person was granted restricted stock units ("RSUs") under the ClearSign Technologies Corporation 2021 Equity Incentive Plan and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

F2 · derivative.expiration_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

SEC source: 0001104659-24-085995 · tm2420897-2_4seq1.xml · derivative · entry 1

Silva Gil Todd · CIK 0002028266 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 12,364

Underlying: Common Stock · 12,364 shares

Expires not disclosed

F1 · derivative.exercise_price: As compensation for services as a non-executive director during the quarter ending September 30, 2024, on August 1, 2024, the reporting person was granted restricted stock units ("RSUs") under the ClearSign Technologies Corporation 2021 Equity Incentive Plan, pro-rated based on an appointment date of August 1, 2024, and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

F2 · derivative.expiration_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

SEC source: 0001104659-24-077855 · tm2418827-1_4seq1.xml · derivative · entry 1

Maley David M · CIK 0002021245 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 36,410

Underlying: Common Stock · 22,001 shares

Expires not disclosed

F1 · derivative.exercise_price: The reporting person was granted restricted stock units ("RSUs") under the ClearSign Technologies Corporation 2021 Equity Incentive Plan, consisting of (i) 20,878 RSUs as compensation for services as a non-executive director during the quarter ending September 30, 2024, and (ii) 1,123 RSUs as compensation for services as a member of certain committees of the Issuer's board of directors during the quarter ended June 30, 2024, pro-rated based on an appointment date of May 3, 2024. Each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

F2 · derivative.expiration_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

SEC source: 0001104659-24-077856 · tm2418827-2_4seq1.xml · derivative · entry 1

Schrecker Judith S · CIK 0001850679 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 300,951

Underlying: Common Stock · 29,684 shares

Expires not disclosed

F1 · derivative.exercise_price: As compensation for services as a non-executive director during the quarter ending September 30, 2024, the reporting person was granted restricted stock units ("RSUs") under the ClearSign Technologies Corporation 2021 Equity Incentive Plan and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

F2 · derivative.expiration_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

SEC source: 0001104659-24-077857 · tm2418827-3_4seq1.xml · derivative · entry 1

de Lacy Catharine · CIK 0001966673 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 124,365

Underlying: Common Stock · 21,872 shares

Expires not disclosed

F1 · derivative.exercise_price: As compensation for services as a non-executive director during the quarter ending September 30, 2024, the reporting person was granted restricted stock units ("RSUs") under the ClearSign Technologies Corporation 2021 Equity Incentive Plan and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

F2 · derivative.expiration_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

SEC source: 0001104659-24-075270 · tm2418369-1_4seq1.xml · derivative · entry 5

HOFFMAN Robert Thurston Sr · CIK 0001748409 · 10% owner

clirSPV LLC · CIK 0001747304 · 10% owner

GPclirSPV LLC · CIK 0001749087 · 10% owner

Princeton Opportunity Management LLC · CIK 0001749086 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 1,343,000

Underlying: Common Stock · 1,343,000 shares

Expires not disclosed

F6 · derivative.exercise_price: The pre-funded warrants are exercisable by clirSPV at any time on or after the date of the Purchase Agreement, or June 24, 2024, until fully exercised at an exercise price per share equal to $0.0001, subject to a 19.99% beneficial ownership blocker. The pre-funded warrants have no expiration date

F1 · shares: The securities reported herein were issued to clirSPV LLC ("clirSPV") pursuant to a Securities Purchase Agreement, dated as of June 24, 2024, as amended on June 26, 2024 (as amended, the "Purchase Agreement"), by and among the Issuer and clirSPV, in connection with its participation right to purchase unregistered securities of the Issuer to maintain a 19.99% ownership percentage of the Issuer's outstanding shares of common stock on terms and conditions no different than those offered to other purchasers. Pursuant to the Purchase Agreement, the Issuer issued clirSPV an aggregate of (i) 3,350,000 shares of common stock, (ii) redeemable warrants to purchase up to 7,039,500 shares of common stock and (iii) pre-funded warrants to purchase up to 1,343,000 shares of common stock.

F6 · derivative.exercise_date: The pre-funded warrants are exercisable by clirSPV at any time on or after the date of the Purchase Agreement, or June 24, 2024, until fully exercised at an exercise price per share equal to $0.0001, subject to a 19.99% beneficial ownership blocker. The pre-funded warrants have no expiration date

F6 · derivative.expiration_date: The pre-funded warrants are exercisable by clirSPV at any time on or after the date of the Purchase Agreement, or June 24, 2024, until fully exercised at an exercise price per share equal to $0.0001, subject to a 19.99% beneficial ownership blocker. The pre-funded warrants have no expiration date

F2 · ownership.nature: Mr. Hoffman is the managing member of GPclirSPV LLC which is the managing member of clirSPV, the owner of the shares of common stock. Mr. Hoffman disclaims beneficial ownership of these shares except to the extent of his pecuniary interest in clirSPV. Mr. Hoffman has direct ownership of none of the shares of common stock purchased and a total direct beneficial ownership of 237,464 shares of common stock. clirSPV has direct ownership of 3,350,000 shares of common stock purchased and total direct beneficial ownership of 9,539,857 shares of common stock. GPclirSPV LLC has no direct ownership of the shares purchased and total indirect beneficial ownership of 9,539,857 shares of common stock. Princeton Opportunity Management LLC has no direct ownership of shares purchased and total indirect beneficial ownership of 9,539,857 shares of common stock.

SEC source: 0001104659-24-075270 · tm2418369-1_4seq1.xml · derivative · entry 4

HOFFMAN Robert Thurston Sr · CIK 0001748409 · 10% owner

clirSPV LLC · CIK 0001747304 · 10% owner

GPclirSPV LLC · CIK 0001749087 · 10% owner

Princeton Opportunity Management LLC · CIK 0001749086 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 7,039,500

Underlying: Common Stock · 7,039,500 shares

Expires not disclosed

F5 · derivative.exercise_price: The redeemable warrants are exercisable by clirSPV at any time on or after six (6) months after the date of the Purchase Agreement, or December 24, 2024, until June 24, 2029 at an exercise price per share equal to $1.05, subject to a 19.99% beneficial ownership blocker.

F1 · shares: The securities reported herein were issued to clirSPV LLC ("clirSPV") pursuant to a Securities Purchase Agreement, dated as of June 24, 2024, as amended on June 26, 2024 (as amended, the "Purchase Agreement"), by and among the Issuer and clirSPV, in connection with its participation right to purchase unregistered securities of the Issuer to maintain a 19.99% ownership percentage of the Issuer's outstanding shares of common stock on terms and conditions no different than those offered to other purchasers. Pursuant to the Purchase Agreement, the Issuer issued clirSPV an aggregate of (i) 3,350,000 shares of common stock, (ii) redeemable warrants to purchase up to 7,039,500 shares of common stock and (iii) pre-funded warrants to purchase up to 1,343,000 shares of common stock.

F5 · derivative.exercise_date: The redeemable warrants are exercisable by clirSPV at any time on or after six (6) months after the date of the Purchase Agreement, or December 24, 2024, until June 24, 2029 at an exercise price per share equal to $1.05, subject to a 19.99% beneficial ownership blocker.

F5 · derivative.expiration_date: The redeemable warrants are exercisable by clirSPV at any time on or after six (6) months after the date of the Purchase Agreement, or December 24, 2024, until June 24, 2029 at an exercise price per share equal to $1.05, subject to a 19.99% beneficial ownership blocker.

F2 · ownership.nature: Mr. Hoffman is the managing member of GPclirSPV LLC which is the managing member of clirSPV, the owner of the shares of common stock. Mr. Hoffman disclaims beneficial ownership of these shares except to the extent of his pecuniary interest in clirSPV. Mr. Hoffman has direct ownership of none of the shares of common stock purchased and a total direct beneficial ownership of 237,464 shares of common stock. clirSPV has direct ownership of 3,350,000 shares of common stock purchased and total direct beneficial ownership of 9,539,857 shares of common stock. GPclirSPV LLC has no direct ownership of the shares purchased and total indirect beneficial ownership of 9,539,857 shares of common stock. Princeton Opportunity Management LLC has no direct ownership of shares purchased and total indirect beneficial ownership of 9,539,857 shares of common stock.

SEC source: 0001104659-24-075270 · tm2418369-1_4seq1.xml · nonDerivative · entry 1

HOFFMAN Robert Thurston Sr · CIK 0001748409 · 10% owner

clirSPV LLC · CIK 0001747304 · 10% owner

GPclirSPV LLC · CIK 0001749087 · 10% owner

Princeton Opportunity Management LLC · CIK 0001749086 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 9,539,857

F1 · shares: The securities reported herein were issued to clirSPV LLC ("clirSPV") pursuant to a Securities Purchase Agreement, dated as of June 24, 2024, as amended on June 26, 2024 (as amended, the "Purchase Agreement"), by and among the Issuer and clirSPV, in connection with its participation right to purchase unregistered securities of the Issuer to maintain a 19.99% ownership percentage of the Issuer's outstanding shares of common stock on terms and conditions no different than those offered to other purchasers. Pursuant to the Purchase Agreement, the Issuer issued clirSPV an aggregate of (i) 3,350,000 shares of common stock, (ii) redeemable warrants to purchase up to 7,039,500 shares of common stock and (iii) pre-funded warrants to purchase up to 1,343,000 shares of common stock.

F2 · ownership.nature: Mr. Hoffman is the managing member of GPclirSPV LLC which is the managing member of clirSPV, the owner of the shares of common stock. Mr. Hoffman disclaims beneficial ownership of these shares except to the extent of his pecuniary interest in clirSPV. Mr. Hoffman has direct ownership of none of the shares of common stock purchased and a total direct beneficial ownership of 237,464 shares of common stock. clirSPV has direct ownership of 3,350,000 shares of common stock purchased and total direct beneficial ownership of 9,539,857 shares of common stock. GPclirSPV LLC has no direct ownership of the shares purchased and total indirect beneficial ownership of 9,539,857 shares of common stock. Princeton Opportunity Management LLC has no direct ownership of shares purchased and total indirect beneficial ownership of 9,539,857 shares of common stock.

SEC source: 0001104659-25-016240 · tm257346-1_4seq1.xml · derivative · entry 5

Hinds Brent · CIK 0001888082 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 2,627 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F5 · derivative.exercise_price: On February 22, 2024, the reporting person was granted a one-time bonus of 2,627 PRSUs, and each PRSU represents a right to receive one share of common stock or the cash equivalent thereof.

F6 · derivative.exercise_date: The PRSUs granted on February 22, 2024, vested on May 20, 2024, upon the achievement of certain performance targets established by the Company's compensation committee of the board of directors for the year ended December 31, 2024.

F6 · derivative.expiration_date: The PRSUs granted on February 22, 2024, vested on May 20, 2024, upon the achievement of certain performance targets established by the Company's compensation committee of the board of directors for the year ended December 31, 2024.

SEC source: 0001104659-25-016240 · tm257346-1_4seq1.xml · nonDerivative · entry 2

Hinds Brent · CIK 0001888082 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 74,095

F2 · shares: Represents the payment of the reporting person's tax liability by withholding shares in connection with the vesting of 2,627 PRSUs on May 20, 2024, and calculated based on the closing price of the Company's common stock, as reported on Nasdaq Stock Market, on May 20, 2024 of $0.78.

SEC source: 0001104659-25-016240 · tm257346-1_4seq1.xml · nonDerivative · entry 1

Hinds Brent · CIK 0001888082 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 75,058

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · shares: Reflects the vesting of 2,627 performance-based restricted stock units ("PRSUs") granted to the reporting person on February 22, 2024, into an equal number of shares of the Company's common stock, without the payment of any consideration, pursuant to the ClearSign Technologies Corporation 2021 Equity Incentive Plan (the "2021 Plan").

F1 · price: Reflects the vesting of 2,627 performance-based restricted stock units ("PRSUs") granted to the reporting person on February 22, 2024, into an equal number of shares of the Company's common stock, without the payment of any consideration, pursuant to the ClearSign Technologies Corporation 2021 Equity Incentive Plan (the "2021 Plan").

SEC source: 0001104659-24-052051 · tm2412715-2_4seq1.xml · derivative · entry 1

Maley David M · CIK 0002021245 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 14,409

Underlying: Common Stock · 14,409 shares

Expires not disclosed

F1 · derivative.exercise_price: As compensation for services as a non-executive director during the quarter ending June 30, 2024, on April 23, 2024, the reporting person was granted restricted stock units ("RSUs") under the ClearSign Technologies Corporation 2021 Equity Incentive Plan, pro-rated based on an appointment date of April 23, 2024, and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

F2 · derivative.expiration_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

SEC source: 0001104659-24-042671 · tm2410636-3_4seq1.xml · derivative · entry 1

Schrecker Judith S · CIK 0001850679 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 271,267

Underlying: Common Stock · 26,658 shares

Expires not disclosed

F1 · derivative.exercise_price: As compensation for services as a non-executive director during the quarter ending June 30, 2024, the reporting person was granted restricted stock units ("RSUs") under the ClearSign Technologies Corporation 2021 Equity Incentive Plan and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

F2 · derivative.expiration_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

SEC source: 0001104659-24-042669 · tm2410636-2_4seq1.xml · derivative · entry 1

HOFFMAN Robert Thurston Sr · CIK 0001748409 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 224,311

Underlying: Common Stock · 20,408 shares

Expires not disclosed

F1 · derivative.exercise_price: As compensation for services as a non-executive director during the quarter ending June 30, 2024, the reporting person was granted restricted stock units ("RSUs") under the ClearSign Technologies Corporation 2021 Equity Incentive Plan and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

F2 · derivative.expiration_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

SEC source: 0001104659-24-042667 · tm2410636-1_4seq1.xml · derivative · entry 1

de Lacy Catharine · CIK 0001966673 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 102,493

Underlying: Common Stock · 19,642 shares

Expires not disclosed

F1 · derivative.exercise_price: As compensation for services as a non-executive director during the quarter ending June 30, 2024, the reporting person was granted restricted stock units ("RSUs") under the ClearSign Technologies Corporation 2021 Equity Incentive Plan and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

F2 · derivative.expiration_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

SEC source: 0001104659-24-027584 · tm247292-3_4seq1.xml · derivative · entry 4

Hinds Brent · CIK 0001888082 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 2,627

Underlying: Common Stock · 2,627 shares

Expires not disclosed

F5 · derivative.exercise_price: Represents a one-time bonus performance-based RSU ("PRSUs") grant to the reporting person, and each PRSU represents a right to receive one share of common stock or the cash equivalent thereof.

F6 · derivative.exercise_date: The PRSUs granted on February 22, 2024 will fully vest upon the achievement of certain performance targets established by the Company's compensation committee of the board of directors for the year ending December 31, 2024. If the reporting person does not achieve the established performance targets, which will be measured over the year ending December 31, 2024, the PRSUs will not vest and will be forfeited.

F6 · derivative.expiration_date: The PRSUs granted on February 22, 2024 will fully vest upon the achievement of certain performance targets established by the Company's compensation committee of the board of directors for the year ending December 31, 2024. If the reporting person does not achieve the established performance targets, which will be measured over the year ending December 31, 2024, the PRSUs will not vest and will be forfeited.

SEC source: 0001104659-24-027584 · tm247292-3_4seq1.xml · derivative · entry 3

Hinds Brent · CIK 0001888082 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 7,547

Underlying: Common Stock · 7,547 shares

Expires not disclosed

F3 · derivative.exercise_price: Represents a one-time bonus restricted stock unit ("RSUs") grant to reporting person for services as an executive officer for the year ended December 31, 2023, and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F4 · derivative.exercise_date: The RSUs granted on February 22, 2024 vest in three equal installments commencing on the first anniversary of the grant date.

F4 · derivative.expiration_date: The RSUs granted on February 22, 2024 vest in three equal installments commencing on the first anniversary of the grant date.

SEC source: 0001104659-24-027584 · tm247292-3_4seq1.xml · nonDerivative · entry 2

Hinds Brent · CIK 0001888082 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 72,431

F2 · shares: Represents the payment of the reporting person's tax liability by withholding shares incident to the receipt of the Company's common stock issued on February 22, 2024 based on the closing price of the Company's common stock on February 22, 2024 of $1.06.

SEC source: 0001104659-24-027584 · tm247292-3_4seq1.xml · nonDerivative · entry 1

Hinds Brent · CIK 0001888082 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 88,951

F1 · shares: Represents a one-time bonus grant to the reporting person for services as an executive officer for the year ended December 31, 2023. The number of shares awarded is based on the closing price of the Company's common stock on February 22, 2024 of $1.06.

SEC source: 0001104659-24-027573 · tm247292-1_4seq1.xml · nonDerivative · entry 2

Deller Colin James · CIK 0001766480 · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 121,306

F2 · shares: Represents the payment of the reporting person's tax liability by withholding shares incident to the receipt of the Company's common stock issued on February 22, 2024 based on the closing price of the Company's common stock on February 22, 2024 of $1.06.

SEC source: 0001104659-24-027573 · tm247292-1_4seq1.xml · nonDerivative · entry 1

Deller Colin James · CIK 0001766480 · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 186,408

F1 · shares: Represents a one-time bonus grant to reporting person for services as an executive officer for the year ended December 31, 2023. The number of shares awarded is based on the closing price of the Company's common stock on February 22, 2024 of $1.06.

SEC source: 0001104659-24-045881 · tm2411542-1_4aseq1.xml · derivative · entry 1

Hinds Brent · CIK 0001888082 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,641

Underlying: Common Stock · 22,641 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents a one-time bonus restricted stock unit ("RSUs") grant to reporting person for services as an executive officer for the year ended December 31, 2023, and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs granted on February 22, 2024 vest in three equal installments commencing on the first anniversary of the grant date.

F2 · derivative.expiration_date: The RSUs granted on February 22, 2024 vest in three equal installments commencing on the first anniversary of the grant date.

SEC source: 0001104659-24-011141 · tm245384-1_4seq1.xml · derivative · entry 3

Hinds Brent · CIK 0001888082 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,254

Underlying: Common Stock · 10,126 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F4 · derivative.exercise_price: On February 2, 2023, the reporting person was granted 30,380 RSUs as a one-time bonus for services as an executive officer for the year ended December 31, 2022, and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F1 · shares: Represents the vesting of 10,126 restricted stock units ("RSUs").

F5 · derivative.exercise_date: The RSUs granted on February 2, 2023 vest in three equal annual installments commencing on the first anniversary of the grant date.

F5 · derivative.expiration_date: The RSUs granted on February 2, 2023 vest in three equal annual installments commencing on the first anniversary of the grant date.

SEC source: 0001104659-24-011141 · tm245384-1_4seq1.xml · nonDerivative · entry 2

Hinds Brent · CIK 0001888082 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 65,549

F3 · shares: Represents the payment of the reporting person's tax liability by withholding shares incident to the vesting of the RSUs that vested on February 2, 2024.

SEC source: 0001104659-24-011141 · tm245384-1_4seq1.xml · nonDerivative · entry 1

Hinds Brent · CIK 0001888082 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 69,261

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · shares: Represents the vesting of 10,126 restricted stock units ("RSUs").

F2 · price: RSUs convert to common stock on a one-for-one basis.

SEC source: 0001014108-24-000005 · primary_doc.xml · nonDerivative · entry 1

HOFFMAN Robert Thurston Sr · CIK 0001748409 · Director · 10% owner

clirSPV LLC · CIK 0001747304 · 10% owner

GPclirSPV LLC · CIK 0001749087 · 10% owner

Princeton Opportunity Management LLC · CIK 0001749086 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Note

Disclosed balance after: 6,189,857

F1 · kind: Note: clirSPV LLC distributed 1,269,705 shares of ClearSign Technologies Corp. to certain of its members. To the knowledge of Mr. Hoffman, none of such members holds 5% or more of the Common Stock of ClearSign Technologies Corp. after such distribution.

F2 · ownership.nature: Note: Mr. Hoffman is the managing member of GPclirSPV LLC which is the managing member of clirSPV LLC, the owner of the common stock. Mr. Hoffman disclaims beneficial ownership of these shares except to the extent of his pecuniary interest in clirSPV LLC. clirSPV LLC has distributed 1,269,705 shares of ClearSign Technologies Corp. to certain of its members pursuant to their rights to cause such distributions. clirSPV LLC has direct ownership of 6,189,857 shares of Common Stock. GPclirSPV, LLC has no direct ownership of the shares purchased and total indirect beneficial ownership of 6,189,857 shares of Common Stock. Princeton Opportunity Management LLC has no direct ownership of shares purchased and total indirect beneficial ownership of 6,189,857 shares of Common Stock

SEC source: 0001104659-24-000874 · tm241812-3_4seq1.xml · derivative · entry 1

Schrecker Judith S · CIK 0001850679 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 244,609

Underlying: Common Stock · 24,415 shares

Expires not disclosed

F1 · derivative.exercise_price: As compensation for services as a non-executive director during the quarter ending March 31, 2024, the reporting person was granted restricted stock units ("RSUs") under the ClearSign Technologies Corporation 2021 Equity Incentive Plan and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

F2 · derivative.expiration_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

SEC source: 0001104659-24-000871 · tm241812-2_4seq1.xml · derivative · entry 1

HOFFMAN Robert Thurston Sr · CIK 0001748409 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 203,903

Underlying: Common Stock · 18,691 shares

Expires not disclosed

F1 · derivative.exercise_price: As compensation for services as a non-executive director during the quarter ending March 31, 2024, the reporting person was granted restricted stock units ("RSUs") under the ClearSign Technologies Corporation 2021 Equity Incentive Plan and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

F2 · derivative.expiration_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

SEC source: 0001104659-24-000863 · tm241812-1_4seq1.xml · derivative · entry 1

de Lacy Catharine · CIK 0001966673 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 82,851

Underlying: Common Stock · 17,990 shares

Expires not disclosed

F1 · derivative.exercise_price: As compensation for services as a non-executive director during the quarter ending March 31, 2024, the reporting person was granted restricted stock units ("RSUs") under the ClearSign Technologies Corporation 2021 Equity Incentive Plan and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

F2 · derivative.expiration_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

SEC source: 0001104659-23-106899 · tm2327697-3_4seq1.xml · derivative · entry 1

Schrecker Judith S · CIK 0001850679 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 220,194

Underlying: Common Stock · 23,809 shares

Expires not disclosed

F1 · derivative.exercise_price: As compensation for services as a non-executive director during the quarter ending December 31, 2023, the reporting person was granted restricted stock units ("RSUs") under the ClearSign Technologies Corporation 2021 Equity Incentive Plan and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

F2 · derivative.expiration_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

SEC source: 0001104659-23-106894 · tm2327697-2_4seq1.xml · derivative · entry 1

HOFFMAN Robert Thurston Sr · CIK 0001748409 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 185,212

Underlying: Common Stock · 19,047 shares

Expires not disclosed

F1 · derivative.exercise_price: As compensation for services as a non-executive director during the quarter ending December 31, 2023, the reporting person was granted restricted stock units ("RSUs") under the ClearSign Technologies Corporation 2021 Equity Incentive Plan and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

F2 · derivative.expiration_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

SEC source: 0001104659-23-106901 · tm2327697-4_4seq1.xml · derivative · entry 1

de Lacy Catharine · CIK 0001966673 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 64,861

Underlying: Common Stock · 18,333 shares

Expires not disclosed

F1 · derivative.exercise_price: As compensation for services as a non-executive director during the quarter ending December 31, 2023, the reporting person was granted restricted stock units ("RSUs") under the ClearSign Technologies Corporation 2021 Equity Incentive Plan and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

F2 · derivative.expiration_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

SEC source: 0001104659-23-106892 · tm2327697-1_4seq1.xml · derivative · entry 1

DiElsi Gary J. · CIK 0001939971 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 115,993

Underlying: Common Stock · 18,571 shares

Expires not disclosed

F1 · derivative.exercise_price: As compensation for services as a non-executive director during the quarter ending December 31, 2023, the reporting person was granted restricted stock units ("RSUs") under the ClearSign Technologies Corporation 2021 Equity Incentive Plan and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

F2 · derivative.expiration_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

SEC source: 0001104659-23-078718 · tm2320744-3_4.xml · derivative · entry 1

Schrecker Judith S · CIK 0001850679 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 196,385

Underlying: Common Stock · 19,209 shares

Expires not disclosed

F1 · derivative.exercise_price: As compensation for services as a non-executive director during the quarter ending September 30, 2023, the reporting person was granted restricted stock units ("RSUs") under the ClearSign Technologies Corporation 2021 Equity Incentive Plan and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

F2 · derivative.expiration_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

SEC source: 0001104659-23-078695 · tm2320744-2_4.xml · derivative · entry 1

HOFFMAN Robert Thurston Sr · CIK 0001748409 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 166,165

Underlying: Common Stock · 14,705 shares

Expires not disclosed

F1 · derivative.exercise_price: As compensation for services as a non-executive director during the quarter ending September 30, 2023, the reporting person was granted restricted stock units ("RSUs") under the ClearSign Technologies Corporation 2021 Equity Incentive Plan and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

F2 · derivative.expiration_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

SEC source: 0001104659-23-078724 · tm2320744-4_4.xml · derivative · entry 1

de Lacy Catharine · CIK 0001966673 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 46,528

Underlying: Common Stock · 13,602 shares

Expires not disclosed

F1 · derivative.exercise_price: As compensation for services as a non-executive director during the quarter ending September 30, 2023, the reporting person was granted restricted stock units ("RSUs") under the ClearSign Technologies Corporation 2021 Equity Incentive Plan and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F2 · derivative.exercise_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.

F2 · derivative.expiration_date: The RSUs will vest upon the first to occur of: (1) a Change in Control (as defined in the applicable RSU award agreement), (2) the reporting person's Disability (as defined in the applicable RSU award agreement); (3) the reporting person's death; or (4) the reporting person's separation from service.