COLELLA GERALD G

SEC source: 0001127602-18-006760 · form4.xml · derivative · entry 11

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 58,116.117

Underlying: Common Stock · 12,213.298 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.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F5 · derivative.exercise_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant and thereafter vest in three equal annual installments beginning on February 15, 2016, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F5 · derivative.expiration_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant and thereafter vest in three equal annual installments beginning on February 15, 2016, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-18-006760 · form4.xml · derivative · entry 10

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 41,560.731

Underlying: Common Stock · 15,751.575 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F4 · derivative.exercise_date: These RSUs vest in three equal annual installments commencing on February 15, 2019, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F4 · derivative.expiration_date: These RSUs vest in three equal annual installments commencing on February 15, 2019, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-18-006760 · form4.xml · derivative · entry 9

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 63,905.155

Underlying: Common Stock · 30,378.038 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F3 · derivative.exercise_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant and thereafter vest in three equal annual installments beginning on February 15, 2019, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F3 · derivative.expiration_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant and thereafter vest in three equal annual installments beginning on February 15, 2019, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-18-006760 · form4.xml · nonDerivative · entry 7

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 42,293.742

F2 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the reporting person.

SEC source: 0001127602-18-006760 · form4.xml · nonDerivative · entry 6

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 69,706.742

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 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-18-006760 · form4.xml · nonDerivative · entry 5

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 62,321.742

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 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-18-006760 · form4.xml · nonDerivative · entry 4

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 53,385.742

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 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-18-006760 · form4.xml · nonDerivative · entry 3

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 42,347.742

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 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-18-006760 · form4.xml · nonDerivative · entry 2

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 26,694.742

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 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-18-006760 · form4.xml · nonDerivative · entry 1

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 17,237.948

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 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-18-005390 · form4.xml · derivative · entry 1

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 70,329.415

Underlying: Common Stock · 6,425.406 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F2 · kind: This transaction reflects the forfeiture of RSUs due to performance criteria.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F3 · derivative.exercise_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant and thereafter vest in three equal annual installments beginning on February 15, 2018, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F3 · derivative.expiration_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant and thereafter vest in three equal annual installments beginning on February 15, 2018, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-18-001724 · form4.xml · nonDerivative · entry 1

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Indirect · By Gerald G. Colella Living Trust

Disclosed balance after: 46,296

F1 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the reporting person.

F2 · price: This transaction was executed in multiple trades at prices ranging from $95.30 to $96.60. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide, upon request, the full information regarding the number of shares and prices at which the transaction was effected.

SEC source: 0001127602-17-034793 · form4.xml · nonDerivative · entry 1

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Indirect · By Gerald G. Colella Living Trust

Disclosed balance after: 56,296

F1 · price: This transaction was executed in multiple trades at prices ranging from $95.200 to $95.350. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide, upon request, the full information regarding the number of shares and prices at which the transaction was effected.

SEC source: 0001127602-17-019143 · form4.xml · nonDerivative · entry 1

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Indirect · by Gerald G. Colella Living Trust

Disclosed balance after: 61,296

F1 · price: This transaction was executed in multiple trades at prices ranging from $79.25 to $79.40. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide, upon request, the full information regarding the number of shares and prices at which the transaction was effected.

SEC source: 0001127602-17-017912 · form4.xml · derivative · entry 4

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 76,754.821

Underlying: Common Stock · 9,487.666 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.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F3 · derivative.exercise_date: These RSUs originally were scheduled to vest in two equal installments based on the Company's achievement of certain performance criteria for the period ending June 30, 2017 and June 30, 2018. On May 10, 2017, the Compensation Committee accelerated in full the vesting of these RSUs to May 11, 2017 as a result of the Company's 100% achievement of the performance criteria.

F3 · derivative.expiration_date: These RSUs originally were scheduled to vest in two equal installments based on the Company's achievement of certain performance criteria for the period ending June 30, 2017 and June 30, 2018. On May 10, 2017, the Compensation Committee accelerated in full the vesting of these RSUs to May 11, 2017 as a result of the Company's 100% achievement of the performance criteria.

SEC source: 0001127602-17-017912 · form4.xml · nonDerivative · entry 2

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,024.65

F2 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the reporting person.

SEC source: 0001127602-17-017912 · form4.xml · nonDerivative · entry 1

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 9,488.65

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 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001644440-17-000077 · wf-form4_149401704597214.xml · nonDerivative · entry 1

COLELLA GERARD G · CIK 0001256715 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,967

F1 · price: Issued pursuant to the GCP non-employee director compensation program in partial payment of the 2017 retainer.

SEC source: 0001127602-17-013852 · form4.xml · nonDerivative · entry 1

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 63,796.984

F1 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the reporting person.

F2 · price: This transaction was executed in multiple trades at prices ranging from $67.65 to $69.20. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide, upon request, the full information regarding the number of shares and prices at which the transaction was effected.

SEC source: 0001127602-17-006624 · form4.xml · derivative · entry 11

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 53,688.95

Underlying: Common Stock · 11,037 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.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F8 · derivative.exercise_date: These RSUs vest in three equal annual installments commencing on February 15, 2017, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F8 · derivative.expiration_date: These RSUs vest in three equal annual installments commencing on February 15, 2017, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-17-006624 · form4.xml · derivative · entry 10

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 86,242.487

Underlying: Common Stock · 15,653 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.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F7 · derivative.exercise_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant and thereafter vest in three equal annual installments beginning on February 15, 2017, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F7 · derivative.expiration_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant and thereafter vest in three equal annual installments beginning on February 15, 2017, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-17-006624 · form4.xml · derivative · entry 9

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 64,725.95

Underlying: Common Stock · 9,456 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.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F6 · derivative.exercise_date: These RSUs vest in three equal annual installments commencing on February 15, 2016, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F6 · derivative.expiration_date: These RSUs vest in three equal annual installments commencing on February 15, 2016, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-17-006624 · form4.xml · derivative · entry 8

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 101,895.487

Underlying: Common Stock · 12,213 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.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F5 · derivative.exercise_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant and thereafter vest in three equal annual installments beginning on February 15, 2016, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F5 · derivative.expiration_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant and thereafter vest in three equal annual installments beginning on February 15, 2016, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-17-006624 · form4.xml · derivative · entry 7

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 74,181.95

Underlying: Common Stock · 22,156.573 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F4 · derivative.exercise_date: These RSUs vest in three equal annual installments commencing on February 15, 2018, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F4 · derivative.expiration_date: These RSUs vest in three equal annual installments commencing on February 15, 2018, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-17-006624 · form4.xml · derivative · entry 6

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 114,108.487

Underlying: Common Stock · 33,234.86 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F3 · derivative.exercise_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant and thereafter vest in three equal annual installments beginning on February 15, 2018, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F3 · derivative.expiration_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant and thereafter vest in three equal annual installments beginning on February 15, 2018, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-17-006624 · form4.xml · nonDerivative · entry 5

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 73,796.984

F2 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the reporting person.

SEC source: 0001127602-17-006624 · form4.xml · nonDerivative · entry 4

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 96,551.984

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 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-17-006624 · form4.xml · nonDerivative · entry 3

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 85,514.984

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 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-17-006624 · form4.xml · nonDerivative · entry 2

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 69,861.984

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 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-17-006624 · form4.xml · nonDerivative · entry 1

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 60,405.984

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 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-17-006132 · form4.xml · derivative · entry 6

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 80,873.627

Underlying: Common Stock · 7,224.563 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F5 · kind: This transaction reflects the forfeiture of RSUs due to performance criteria.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F6 · derivative.exercise_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant and thereafter vest in three equal annual installments beginning on February 15, 2017, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F6 · derivative.expiration_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant and thereafter vest in three equal annual installments beginning on February 15, 2017, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-17-006132 · form4.xml · derivative · entry 5

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 52,025.377

Underlying: Common Stock · 8,035.683 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.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F4 · derivative.exercise_date: The RSUs vest in equal annual installments over three years from the respective original grant date.

F4 · derivative.expiration_date: The RSUs vest in equal annual installments over three years from the respective original grant date.

SEC source: 0001127602-17-006132 · form4.xml · derivative · entry 4

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 88,098.19

Underlying: Common Stock · 12,053.235 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.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F3 · derivative.exercise_date: These RSUs are subject to the achievement of performance criteria determined in the first year of the grant and thereafter vest in equal annual installments over three years.

F3 · derivative.expiration_date: These RSUs are subject to the achievement of performance criteria determined in the first year of the grant and thereafter vest in equal annual installments over three years.

SEC source: 0001127602-17-006132 · form4.xml · nonDerivative · entry 3

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 48,192.984

F2 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the reporting person.

SEC source: 0001127602-17-006132 · form4.xml · nonDerivative · entry 2

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 55,488.984

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 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-17-006132 · form4.xml · nonDerivative · entry 1

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 47,453.301

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 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-16-067584 · form4.xml · nonDerivative · entry 1

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 35,400.066

F1 · price: This transaction was executed in multiple trades at prices ranging from $55.30 to $56.20. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide, upon request, the full information regarding the number of shares and prices at which the transaction was effected.

SEC source: 0001127602-16-062505 · form4.xml · nonDerivative · entry 1

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 37,900.066

F1 · price: This transaction was executed in multiple trades at prices ranging from $46.95 to $47.37. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide, upon request, the full information regarding the number of shares and prices at which the transaction was effected.