Joinder to Sponsor Agreement. Transferee hereby agrees to be bound by:

Joinder to Letter Agreement. Transferee hereby agrees to be bound by paragraph 6(b), paragraph 7(a) (subject to paragraph 7(c)) and paragraphs 11 through 16 of the Letter Agreement; in each case, to the same extent as if Transferee were an original party to the Letter Agreement (but solely for the purpose of the provisions of the Letter Agreement specified above and solely with respect to the Transferee Conversion Shares).

“Joinder Agreement” means a joinder agreement in the form of [Exhibit L].

“Joinder Agreement” means a Joinder Agreement in substantially the form of [Exhibit E].

“Joinder Agreement” shall mean a joinder agreement substantially in the form of [Exhibit 3] to the Security Agreement.

Joinder – Crestview Investor I JOINDER TO SPONSOR AGREEMENT AND LETTER AGREEMENT This Joinder to Sponsor Agreement and Letter Agreement, dated as of ​ (this “Joinder”), is executed by Crestview III USWS, L.P., a Delaware limited partnership (“Transferee”), in favor of U.S. Well Services, Inc., a Delaware corporation (formerly Matlin & Partners Acquisition Corporation) (the “Company”), pursuant to [Section 3(d)] of the Sponsor Agreement (as defined below) and paragraph 7(c) of the Letter Agreement (as defined below). Each capitalized term used and not otherwise defined in this Joinder has the meaning given to such term in the Sponsor Agreement.

“Lender Joinder Agreement” means a joinder agreement in form and substance reasonably satisfactory to the Administrative Agent delivered in connection with [Section 5.13].

“Joinder Agreement” means a joinder agreement substantially in the form of [Exhibit D] executed and delivered in accordance with the provisions of [Section 6.13].

“Joinder Agreement”: each Joinder Agreement, substantially in the form of [Exhibit A], from time to time executed and delivered hereunder pursuant to ​ (b).

“Joinder to Multiparty Guaranty” means a joinder agreement entered into by an Additional Subsidiary Guarantor in substantially the form of [Exhibit E].