Filed Pursuant to Rule 424(b)(3)
Registration No. 333-259731
PROSPECTUS SUPPLEMENT NO. 4
(To the Prospectus dated
May 19, 2022)
Up to 64,020,756 Shares of Common Stock
Up to 13,824,992 Shares of Common Stock Issuable Upon Exercise of Warrants
Up to 5,200,000 Warrants to Purchase Common Stock
This prospectus
supplement supplements the prospectus, dated May 19, 2022 (the “Prospectus”), which forms a part of our registration statement on Form S-1 (No.
333-259731). This prospectus supplement is being filed to update and supplement the information in the Prospectus with certain information contained in our Current Report on Form
8-K filed with the Securities and Exchange Commission on July 15, 2022 (the “Current Report”). Accordingly, we have attached the Current Report to this prospectus supplement.
The Prospectus and this prospectus supplement relate to the issuance by us of an aggregate of up to 13,824,992 shares of our common stock,
$0.0001 par value per share (the “common stock”), which consists of (i) up to 5,200,000 shares of common stock that are issuable upon the exercise of 5,200,000 warrants (the “Private Warrants”) originally
issued in a private placement to LGL Systems Acquisition Holding Company, LLC (the “Sponsor”) in connection with the initial public offering of LGL Systems Acquisition Corp. (“LGL”) and (ii) up to 8,624,992
shares of common stock that are issuable upon the exercise of 8,624,992 warrants (the “Public Warrants” and, together with the Private Warrants, the “Warrants”) originally issued in the initial public offering of
LGL.
The Prospectus and this prospectus supplement also relate to the offer and sale from time to time by the selling securityholders
named in the Prospectus or their permitted transferees (the “selling securityholders”) of (i) up to 64,020,756 shares of common stock consisting of (a) up to 12,500,000 shares of common stock issued in a private placement
pursuant to subscription agreements (the “Subscription Agreements”) entered into on March 15, 2021, (b) up to 2,904,375 shares of common stock issued in a private placement to the Sponsor in connection with the initial public
offering of LGL (the “Founder Shares”), (c) up to 5,200,000 shares of common stock issuable upon exercise of the Private Warrants and (d) up to 43,416,381 shares of common stock (including up to 81,412 shares of common stock
issuable pursuant to outstanding options, 7,465,923 shares of common stock issuable in connection with the vesting and settlement of restricted stock units, and 560,703 shares of common stock that were issued as Earnout Shares on September 17,
2021) pursuant to that certain Amended and Restated Registration Rights Agreement, dated August 26, 2021, between us and the selling securityholders granting such holders registration rights with respect to such shares and (ii) up to
5,200,000 Private Warrants.
The common stock and Warrants are listed on the New York Stock Exchange (“NYSE”) under the
symbols “IRNT” and “IRNT.WS,” respectively. On July 14, 2022, the last reported sales price of our common stock on NYSE was $2.45 per share and the last reported sales price of our Warrants was $0.35 per warrant.
This prospectus supplement should be read in conjunction with the Prospectus, including any amendments or supplements thereto, which is to be
delivered with this prospectus supplement. This prospectus supplement is qualified by reference to the Prospectus, including any amendments or supplements thereto, except to the extent that the information in this prospectus supplement updates and
supersedes the information contained therein.
This prospectus supplement is not complete without, and may not be delivered or utilized
except in connection with, the Prospectus, including any amendments or supplements thereto.
We are an “emerging growth company”
as defined under U.S. federal securities laws and, as such, have elected to comply with reduced public company reporting requirements. The Prospectus complies with the requirements that apply to an issuer that is an emerging growth company.