Exhibit 4.2


 


	
        NUMBER

        C-
	 	SHARES
	 	 	 
	SEE REVERSE FOR CERTAIN DEFINITIONS	 	 
	 	 	 
	 	 	CUSIP 05602L104
	 	 	 


B. RILEY PRINCIPAL
250 MERGER CORP. 


 


CLASS A COMMON
STOCK


 


THIS
CERTIFIES THAT is the owner of fully paid and non-assessable shares of Class A common stock, par value $0.0001 per share (the “Common
Stock”), of B. Riley Principal 250 Merger Corp., a Delaware corporation (the “Company”),
transferable on the books of the Company in person or by duly authorized attorney upon surrender of this certificate properly endorsed.


 


This
certificate is not valid unless countersigned by the Transfer Agent and registered by the Registrar of the Company.


 


Witness
the facsimile signature of a duly authorized signatory of the Company.


 


	 	 	 
	Authorized Signatory	 	Transfer Agent


B. RILEY PRINCIPAL
250 MERGER CORP.


 


The
Company will furnish without charge to each stockholder who so requests, a statement of the powers, designations, preferences and
relative, participating, optional or other special rights of each class of stock or series thereof of the Company and the qualifications,
limitations, or restrictions of such preferences and/or rights. This certificate and the shares represented thereby are issued
and shall be held subject to all the provisions of the Company’s Amended and Restated Certificate of Incorporation and all
amendments thereto and resolutions of the Board of Directors providing for the issue of securities (copies of which may be obtained
from the secretary of the Company), to all of which the holder of this certificate by acceptance hereof assents.


 


The
following abbreviations, when used in the inscription on the face of this certificate, shall be construed as though they were written
out in full according to applicable laws or regulations:


 


	TEN COM	—	as tenants in common	UNIF GIFT MIN ACT	—	 	Custodian	 
	TEN ENT	—	as tenants by the entireties	 	 	(Cust)	 	(Minor)





 


	JT TEN	—	as joint tenants with right of survivorship and not as tenants in common	 	 	
        under Uniform Gifts to Minors Act

        (State)



 






     


     


    




 


Additional abbreviations
may also be used though not in the above list.


 


For value received,
hereby sells, assigns and transfers unto


 


(PLEASE INSERT
SOCIAL SECURITY OR OTHER IDENTIFYING NUMBER(S) OF ASSIGNEE(S))


 


(PLEASE PRINT OR
TYPEWRITE NAME(S) AND ADDRESS(ES), INCLUDING ZIP CODE, OF ASSIGNEE(S))


 


shares of Common
Stock represented by the within Certificate, and hereby irrevocably constitutes and appoints


 


Attorney
to transfer the said shares of Common Stock on the books of the within named Company with full power of substitution in the premises.


 


Dated:


 


	 	 
	 	Notice: The signature(s) to this assignment must correspond with the name as written upon the face of the certificate in every particular, without alteration or enlargement or any change whatever.


Signature(s) Guaranteed:


 


	 	 
	 	 
	 	 
	THE SIGNATURE(S) MUST BE GUARANTEED BY AN ELIGIBLE GUARANTOR INSTITUTION (BANKS, STOCKBROKERS, SAVINGS AND LOAN ASSOCIATIONS AND CREDIT UNIONS WITH MEMBERSHIP IN AN APPROVED SIGNATURE GUARANTEE MEDALLION PROGRAM, PURSUANT TO S.E.C. RULE 17Ad-15 UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED (OR ANY SUCCESSOR RULE).	 
	 	 


As more fully
described in, and subject to the terms and conditions described in, the Company’s final prospectus for its initial public
offering dated , 2021, the holder(s) of this certificate shall be entitled to receive a pro rata portion of certain funds held
in the trust account established in connection with the Company’s initial public offering only in the event that (i) the
Company redeems the shares of Common Stock sold in the Company’s initial public offering and liquidates because it does not
consummate an initial business combination by the date set forth (the “Last Date”) in the Company’s
Amended and Restated Certificate of Incorporation, as the same may be amended from time to time (the “Charter”),
(ii) the Company redeems the shares of Common Stock sold in its initial public offering properly submitted in connection with a
stockholder vote to amend the Charter to modify the substance or timing of the Company’s obligation to redeem 100% of the
Common Stock if it does not consummate an initial business combination by the Last Date, or (iii) if the holder(s) seek(s) to redeem
for cash his, her or its respective shares of Common Stock in connection with a tender offer (or proxy solicitation, solely in
the event the Company seeks stockholder approval of the proposed initial business combination) setting forth the details of a proposed
initial business combination. In no other circumstances shall the holder(s) have any right or interest of any kind in or to the
trust account.