Exhibit 4.1


 


NUMBER UNITS


U-___________


 


SEE REVERSE FOR CERTAIN DEFINITIONS


 


CUSIP ___________


 


METAL SKY STAR ACQUISITION CORPORATION


 


UNITS CONSISTING OF ONE SHARE OF ORDINARY SHARE,
ONE-HALF OF ONE

REDEEMABLE WARRANT AND ONE RIGHT


 


THIS CERTIFIES THAT                         is
the owner of              Units.


 


Each Unit of Metal Sky Star Acquisition Corporation,
Cayman Islands exempt company (the “Company”) (“Unit”) consists of one (1) ordinary share,
par value $0.001 per share (“Ordinary Share”), one redeemable warrant (each whole warrant, a “Warrant”)
and one (1) right (“Right”). Each whole Warrant entitles the holder to purchase one-half of one (1) Ordinary
Share (subject to adjustment) for $11.50 per share (subject to adjustment). Only whole warrants are exercisable. Each Right entitles the
holder to receive one-tenth (1/10) of one Ordinary Share. Each Warrant will become exercisable on the later of (i) the Company’s
completion of a merger, capital stock exchange, asset acquisition, stock purchase, reorganization or other similar business combination
with one or more businesses (each a “Business Combination”), and (ii) twelve (12) months from the effective
date of the registration statement on Form S-1, File No. 333-_______, and will expire unless exercised before 5:00 p.m., New
York City Time, on the date that is five (5) years after the date on which the Company completes its initial Business Combination,
or earlier upon redemption or liquidation. The Ordinary Shares, Warrants and Rights comprising the Units represented by this certificate
are not transferable separately prior to [ ], 2021, unless Ladenburg Thalmann & Co., Inc. elects to allow earlier separate
trading, subject to the Company’s filing of a Current Report on Form 8-K with the Securities and Exchange Commission containing
an audited balance sheet reflecting the Company’s receipt of the gross proceeds of the offering and issuing of a press release announcing
when separate trading will begin. The terms of the Warrants and Rights are governed by a Warrant Agreement dated as of            ,
2021, and a Rights Agreement dated as of            , 2021, between the Company
and VStock Transfer LLC, as Warrant Agent and Right Agent, respectively, 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 and
the Rights Agreement are on file at the office of the Warrant Agent and Right Agent at _______________________________________, and are
available to any Warrant holder and Right holder on written request and without cost.


 


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


 


This certificate shall be governed by and construed
in accordance with the internal laws of the Cayman Islands.


 


Witness the facsimile signature of its duly authorized
officers.


 


	Secretary	 	Chief Executive Officer
	 	 	 
	 	 	 


 






     


     


    

 


METAL SKY STAR ACQUISITION CORPORATION


 


The Company will furnish without charge to each
unitholder who so requests, a statement of the powers, designations, preferences and relative, participating, optional or other special
rights of each class of shares 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	 
	 	 	(Cust)	 	(Minor)
	TEN ENT —as tenants by the entireties	 	 	 
	 	 	Under Uniform Gifts to Minors
	 	 
	JT TEN —as joint tenants with right of survivorship and not as tenants in common	 	Act	 
	 	 	 	(State)


 


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


 


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 with 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) 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 (OR ANY SUCCESSOR RULE UNDER THE SECURITIES
EXCHANGE ACT OF 1934, AS AMENDED).


 


In each case, as more fully described in the Company’s final
prospectus 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 Ordinary Shares sold in its initial public offering and
liquidates because it does not consummate an initial business combination by            ,
202_, (ii) the Company redeems Ordinary Shares sold in its initial public offering in connection with a shareholder vote to amend
the Company’s amended and restated memorandum and articles of association to modify the substance or timing of the Company’s
obligation to redeem 100% of the Ordinary Share if it does not consummate an initial business combination by ______________, 202_, or
(iii) if the holder(s) seek(s) to redeem for cash his, her or its respective Ordinary Shares in connection with a tender
offer (or proxy solicitation, solely in the event the Company seeks shareholder 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.