Eos Energy Storage LLC ("Eos" or the "Company"), a developer and manufacturer of grid-scale battery systems, announced that it has completed the initial closing of the sale of preferred units in a private placement transaction resulting in gross proceeds of approximately $23.0 million. The Company expects to use the net proceeds of the private placement for scale-up of contract manufacturing and commercial deployment of the Eos Aurora 1000|4000 DC battery product. The private placement is being managed by a nationally recognized investment bank.

This notice is issued pursuant to Rule 135c under the Securities Act of 1933, as amended (the "Securities Act"), and shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any offer, solicitation, or sale of the securities in any state or jurisdiction in which such offer, solicitation, or sale would be unlawful prior to the registration or qualification of the securities under the securities laws of such state or jurisdiction.

The securities offered in the private placement have not been registered under the Securities Act, or any state securities laws, and may not be offered or sold in the United States without being registered with the Securities and Exchange Commission ("SEC") or through an applicable exemption from SEC registration requirements. Securities of the Company were offered only to accredited investors.

Eos Energy Storage | www.eosenergystorage.com