Specimen Unit Certificate

Exhibit 4.1

CUSIP G[____]

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

ONE RIGHT TO RECEIVE ONE-TENTH OF ONE SHARE OF COMMON STOCK

THIS CERTIFIES THAT ____________________________________________________________________________

is the owner of _______________________________________________________________________________ Units.

Each Unit (“Unit”) consists of one share of common stock, with $0.00001 par value, of Orisun Acquisition Corp., a Delaware company (the “Company”), one redeemable warrant (“Warrant”) and one right (“Right”) to receive one-tenth (1/10) of a share of common stock. Each redeemable Warrant entitles the holder thereof to purchase one-half (1/2) of a share of common stock at a price of $11.50 per full share (subject to adjustment), upon the later to occur of (i) the Company’s completion of a merger, share exchange, asset acquisition, share purchase, recapitalization, reorganization or other similar business combination with one or more businesses or entities (a “Business Combination”) or (ii) one year following the date that the registration statement (file number: 333-[___], the “Registration Statement”) for the Company’s initial public offering (the “Offering”) is effective, i.e., [*], 2019. Every ten Rights entitles the holder thereof to receive one share of common stock upon consummation of the Company’s initial Business Combination. The common stock, Rights and Warrants comprising the Units represented by this certificate are not transferable separately prior to the 90th day after the date of the Registration Statement, unless Chardan Capital Markets, LLC (“Chardan”) determines that an earlier date is acceptable, but in no event will the common stock, Rights and Warrants be traded separately until the Company files with the Securities and Exchange Commission (the “SEC”) a current report on Form 8-K which includes an audited balance sheet reflecting the receipt by the Company of the gross proceeds from its Offering including the proceeds received by the Company from the exercise of the over-allotment option thereto, if the over-allotment option is exercised. If Chardan allows separate trading of the common stock, Rights and Warrants prior to the 90th day after the date of the Registration Statement, the Company will issue a press release and file a Current Report on Form 8-K with the SEC announcing when such separate trading shall begin.

The terms of the Warrants and Rights are governed by a warrant agreement (the “Warrant Agreement”), dated as of [*], 2019, and a rights agreement (the “Rights Agreement”), dated as of [*], 2019, respectively, both between the Company and American Stock Transfer & Trust Company, LLC, as the warrant agent and 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. Copies of the Rights Agreement and the Warrant Agreement are on file at the office of American Stock Transfer & Trust Company, LLC at 6201 15^th Avenue, Brooklyn, New York, 11219, and are available to any Warrant Holder or Rights holder, respectively, 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.

This Unit Certificate shall be governed and construed in accordance with the internal laws of the State of New York, without regard to conflicts of laws principles thereof.

Orisun Acquisition 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 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:

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

For value received, ___________________________ hereby sell(s), assign(s) and transfer(s) unto

PLEASE INSERT SOCIAL SECURITY OR OTHER

IDENTIFYING NUMBER OF ASSIGNEE(S)

Dated ______________

Signature(s) Guaranteed:

The holder of this certificate shall be entitled to receive funds with respect to the underlying ordinary shares from the trust fund only in the event of the Company’s liquidation upon failure to consummate a business combination or if the holder seeks to convert his or her respective ordinary shares underlying the unit upon consummation of such business combination or in connection with certain amendments to the Company’s Amended and Restated Memorandum and Articles of Association. In no other circumstances shall the holder have any right or interest of any kind in or to the trust fund.

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