Exhibit 4.1


 


	 	NUMBER

    U-__________	 	UNITS
	 	 	 	 
	 	SEE REVERSE FOR CERTAIN DEFINITIONS	ALLEGRO MERGER CORP.	 


 


CUSIP 01749N 301


 


UNITS CONSISTING OF
ONE SHARE OF COMMON STOCK, ONE RIGHT AND


ONE WARRANT


 


THIS CERTIFIES THAT
_______________________________________________


 


is the owner of
_________________________________________________ Units.


 


Each Unit (“Unit”) consists
of one (1) share of common stock, par value $.0001 per share (“Common Stock”), of Allegro Merger Corp., a Delaware
corporation (the “Company”), one right (“Right(s)”) and one warrant (“Warrant(s)”). Each Right
entitles the holder to receive one-tenth (1/10) of a share of Common Stock upon consummation of a Business Combination (defined
below). Each Warrant entitles the holder to purchase one share of Common Stock for $10.50 per share (subject to adjustment). 
Each Warrant will become exercisable on the later of (i) 30 days after the Company’s completion of an initial merger,
capital stock exchange, asset acquisition, or other similar business combination with one or more businesses or entities (a “Business
Combination”) and (ii) 12 months from the closing of the Company’s initial public offering (“IPO”), and
will expire unless exercised before 5:00 p.m., New York City Time, on the fifth anniversary of the completion of an initial Business
Combination, or earlier upon redemption or liquidation. The Common Stock and Warrant(s) comprising the Unit(s) represented
by this certificate are not transferable separately prior to the 52nd day after the date of the prospectus relating to the Company’s
IPO, subject to earlier separation in the discretion of Cantor Fitzgerald & Co. provided that the Company has filed with the
Securities and Exchange Commission a Current Report on Form 8-K which includes an audited balance sheet reflecting the Company’s
receipt of the gross proceeds of the IPO and issued a press release announcing when separate trading will begin. The terms of the
Rights are governed by a Rights Agreement, dated as of ________ ___, 2018, between the Company and Continental Stock Transfer &
Trust Company, as Rights Agent, and are subject to the terms and provisions contained therein, all of which terms and provisions
the holder of this certificate consents to by acceptance hereof. The terms of the Warrants are governed by a Warrant Agreement,
dated as of _______, 2018, between the Company and Continental Stock Transfer & Trust Company, as Warrant Agent, and are subject
to the terms and provisions contained therein, all of which terms and provisions the holder of this certificate consents to by
acceptance hereof. Copies of the Warrant Agreement are on file at the office of the Warrant Agent at 1 State Street Plaza, New
York, New York 10004, and are available to any Warrant holder on written request and without cost.


 


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


Witness the facsimile
seal of the Company and the facsimile signatures of its duly authorized officers.


 


By


 


	 	 		 
	 	 	 
	 	 	 
	 	Chairman	Secretary
	 	 	 
	 	 	 




 




     


     


    

 


Allegro Merger Corp.


 


The Company will furnish
without charge to each shareholder 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.


 


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.


 


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)


 


 


 






 


 


 






 


	 	 Units


 


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


 


	 	 Attorney


to transfer the said Units 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(s) of this certificate shall be entitled to receive
a pro-rata portion of the funds from the trust account with respect to the common stock underlying this certificate only in the
event that (i) the Corporation is forced to liquidate because it does not consummate an initial business combination within the
period of time set forth in the Corporation’s Amended and Restated Certificate of Incorporation, as the same may be amended
from time to time (the “Charter”) or (ii) if the holder seeks to convert his shares upon consummation of, or sell his
shares in a tender offer in connection with, an initial business combination or in connection with certain amendments to the Charter.
In no other circumstances shall the holder(s) have any right or interest of any kind in or to the trust account.