Photon Control Inc.

Notice of Change in Corporate Structure pursuant to Section 4.9 of National Instrument 51-102 – Continuous Disclosure Obligations

Item 1. Names of the parties to the transaction

Photon Control Inc. (" Photon Control ")

MKS Instruments, Inc. (" MKS ")

1302998 B.C. Ltd. (the " Purchaser ")

Item 2. Description of the transaction

On July 15, 2021, pursuant to an arrangement agreement dated May 10, 2021 (the " Arrangement Agreement ") between Photon Control, MKS and the Purchaser, a whollyowned subsidiary of MKS, Photon Control completed a plan of arrangement under the Business Corporations Act (British Columbia) (the " Arrangement ") whereby the Purchaser acquired all of the issued and outstanding common shares of Photon Control (the " Common Shares ") in exchange for C$3.60 in cash consideration per Common Share (the " Consideration "), without interest and less applicable withholding taxes. Holders of Photon Control options are entitled to receive, within 10 days of the effective date of the Arrangement, for each of their options, a cash payment equal to the amount, if any, by which the Consideration exceeds the exercise price payable for each Photon Control share underlying each such option, net of applicable withholding taxes.

The Arrangement was previously approved by Photon Control securityholders at the annual general and special meeting of securityholders held on June 29, 2021 (the " Meeting "). The British Columbia Supreme Court issued a final order approving the Arrangement on July 2, 2021.

Photon Control has applied to have the Common Shares delisted from the Toronto Stock Exchange. Photon Control anticipates such delisting to become effective as of the close of markets on July 16, 2021.

Item 3. Effective date of the transaction

The effective date of the Arrangement is July 15, 2021.

Item 4. Names of each party that ceased to be a reporting issuer subsequent to the transaction and of each continuing entity

Photon Control has applied with all applicable Canadian securities regulatory authorities to cease to be a reporting issuer under applicable Canadian securities laws.

Item 5. Date of the reporting issuer's first financial year-end after the transaction

Not applicable.

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• Item 6. The periods, including the comparative periods, if any, of the interim and annual financial statements required to be filed for the reporting issuer's first financial year after the transaction

Not applicable.

Item 7. Documents filed under NI 51-102 that described the transaction and where those documents can be found in electronic format

Not applicable.

Dated: July 15, 2021.