Custom Truck One Source (CTOS) SC 13D Custom Truck One Source / EIN MARK ownership change

Exhibit 1

JOINT FILING AGREEMENT

In accordance with Rule 13d-1(k)(1) promulgated under the Securities Exchange Act of 1934, as amended, the undersigned hereby agree that they are jointly filing this statement on Schedule 13D. Each of them is responsible for the timely filing of such statement and any amendments thereto, and for the completeness and accuracy of the information concerning such person contained therein; but none of them is responsible for the completeness or accuracy of the information concerning the other persons making the filing, unless such person knows or has reason to believe that such information is inaccurate.

IN WITNESS WHEREOF, the undersigned hereby execute this Joint Filing Agreement as of the 13^th day of April, 2021.

Capitol Acquisition Management IV LLC
By:	/s/ Mark Ein
Name: Mark Ein
Title:	CEO
Capitol Acquisition Founder IV LLC
By:	/s/ Dyson Dryden
Name: Dyson Dryden
Title:	CFO
/s/ Mark Ein
Mark Ein
/s/ Dyson Dryden
Dyson Dryden