EX-1.2

Exhibit 1.2

Execution Version

THIRD AMENDMENT TO UNDERWRITING AGREEMENT

THIS THIRD AMENDMENT TO UNDERWRITING AGREEMENT (this “Amendment”) is made and entered into as of October 18, 2023 by and between Spectaire Holdings Inc. (formerly known as Perception Capital Corp. II), a Delaware corporation (the “Company”), and Jefferies LLC (“Jefferies”), and amends that certain Underwriting Agreement dated as of October 27, 2021, as amended by that certain First Amendment to Underwriting Agreement dated as of March 23, 2023 and that certain Second Amendment to Underwriting Agreement dated as of October 16, 2023 (as amended, the “Underwriting Agreement”), by and between the Company and Jefferies, as representative of the several underwriters named therein (collectively, the “Parties”). Capitalized terms used but not otherwise defined herein shall have the meanings ascribed to such terms in the Underwriting Agreement.

WHEREAS, the Parties desire to amend certain provisions of the Underwriting Agreement pursuant to Section 19 of the Underwriting Agreement.

NOW, THEREFORE, in consideration of the covenants and agreements contained herein, and certain other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Parties, intending to be legally bound, hereby agree as follows:

1. Amendment to the Underwriting Agreement. Effective as of the execution hereof, clause (2) of Section 2(e)(i) of the Underwriting Agreement is hereby deleted and replaced with the following:

(2)

Subject to clause (4) below, the Closing Deferred Cash Payment (as defined below) payable in cash to Jefferies LLC, individually and not as the Representative of the Underwriters, for its own account only and not on behalf of or for the accounts of the several Underwriters, no later than six (6) months following the consummation of the initial Business Combination shall be equal to $1,500,000 (the “Closing Deferred Cash Payment”) with the remaining $4,135,000 of the Deferred Discount (the “Deferred Cash Obligation”) being due and payable in cash to Jefferies LLC, individually and not as the Representative of the Underwriters, for its own account only and not on behalf of or for the accounts of the several Underwriters, no later than twenty-four (24) months following the consummation of the initial Business Combination; provided, however, if, following the consummation of the initial Business Combination and prior to the six-month anniversary of the consummation of the initial Business Combination, the Company raises at least $10.0 million of additional capital (whether debt or equity) (excluding the transactions set forth on Schedule A hereto), the Company shall pay in cash to Jefferies LLC the Closing Deferred Cash Payment concurrently with the closing of such additional capital raise.

2. No Further Amendment. The Parties agree that, except as provided herein, all other provisions of the Underwriting Agreement shall continue unmodified, in full force and effect and constitute legal and binding obligations of all parties thereto in accordance with its terms. This Amendment forms an integral and inseparable part of the Underwriting Agreement.

3. References.

(a) All references to the “Agreement” (including “hereof,” “herein,” “hereunder,” “hereby” and “this Agreement”) in the Underwriting Agreement shall refer to the Underwriting Agreement as amended by this Amendment. Notwithstanding the foregoing, references to the date of the Underwriting Agreement (as amended hereby) and references in the Underwriting Agreement to “the date hereof,” “the date of this Agreement” and terms of similar import shall in all instances continue to refer to October 27, 2021.


SPECTAIRE HOLDINGS INC. (formerly known as Perception Capital Corp. II)

By:		/s/ Rick Gaenzle
Name:		Rick Gaenzle
Title:		Chief Executive Officer


JEFFERIES LLC

By:		/s/ Tina Pappas
Name:		Tina Pappas
Title:		Managing Director