Exhibit 4.5


 


	 	NUMBER	RIGHTS
	 	 	 
	 	______R	 


 


ALLEGRO MERGER CORP.


 


INCORPORATED UNDER
THE LAWS OF DELAWARE


 


RIGHT


 


SEE REVERSE FOR

CERTAIN DEFINITIONS


 


	 	 	CUSIP 01749N 129


 


THIS
CERTIFIES THAT, for value received


 


is the registered holder of a right or rights (the “Right”)
to automatically receive one-tenth of one share of common stock, par value $.0001 per share (“Common Stock”), of Allegro
Merger Corp. (the “Company”) for each Right evidenced by this Right Certificate on the Company’s completion of
an initial business combination (as defined in the prospectus relating to the Company’s initial public offering (“Prospectus”))
upon surrender of this Right Certificate pursuant to the Rights Agreement between the Company and Continental Stock Transfer &
Trust Company. In no event will the Company be required to net cash settle any Right.


Upon liquidation
of the Company in the event an initial business combination is not consummated during the required period as identified in the
Company’s Amended and Restated Certificate of Incorporation, the Right(s) shall expire and be worthless. The holder of a
Right shall have no right or interest of any kind in the Company’s trust account (as defined in the Prospectus).


Upon due presentment
for registration of transfer of the Right Certificate at the office or agency of Continental Stock Transfer & Trust Company,
the Right Agent, a new Right Certificate or Right Certificates of like tenor and evidencing in the aggregate a like number of Rights
shall be issued to the transferee in exchange for this Right Certificate, without charge except for any applicable tax or other
governmental charge.


The Company and
the Right Agent may deem and treat the registered holder as the absolute owner of this Right Certificate (notwithstanding any notation
of ownership or other writing hereon made by anyone), for the purpose of any conversion hereof, of any distribution to the registered
holder, and for all other purposes, and neither the Company nor the Right Agent shall be affected by any notice to the contrary.


Holders of Rights
are not entitled to any of the rights of a stockholder of the Company.


 


                  Dated:


 


	 	 		 
	 	 	 
	 	 	 
	 	CHAIRMAN	SECRETARY
	 	 	 
	 	 	 




 



     


     


    

 





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	 under Uniform Gifts to Minors
	 	 	and not as tenants in common	 Act ______________
	 	 	 	 	 (State)


 


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


 


Allegro Merger Corp.


 


The Company will furnish
without charge to each shareholder who so requests 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 rights represented thereby are issued and shall be held subject to
all the provisions of the Rights Agreement, and all amendments thereto, to all of which the holder of this certificate by acceptance
hereof assents.


 


For value received, ___________________________
hereby sell, assign and transfer unto


 


PLEASE INSERT SOCIAL SECURITY OR OTHER


IDENTIFYING NUMBER OF ASSIGNEE


 


	 	 
	 	 


 


 


 






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


 





 








 


 





 



 


 


 






Rights represented by the within Certificate, and do hereby
irrevocably constitute and appoint


 


	 	Attorney


to transfer the said Rights on the books
of the within named Company will full power of substitution in the premises.


 


	Dated	 	 


 


	 	 	 
	 	Notice:	The signature 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) SHOULD 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).


 


The holder of this certificate shall have no right or interest
of any kind in or to the funds held in the Company’s trust fund (as defined in the Prospectus).