附件2.2

参与协议

这份参与协议，系由以下各方于2024年9月16日缔结：入社协议Keen Vision Acquisition Corporation，一家英属维尔京群岛商业公司（母公司），Medera Inc.，一家开曼群岛获豁免公司（权益代理”), KVAC (Cayman) Limited, a Cayman Islands exempted company and wholly owned subsidiary of the Parent (“收购方”) and KVAC MS (Cayman) Limited, a Cayman Islands exempted company and wholly owned subsidiary of Acquirer (“合并子公司”). Reference is made to that certain Merger Agreement (the “合并协议”), dated as of September 3, 2024, entered into by and between Parent and the Company. Capitalized terms used but not otherwise defined herein shall have the meanings ascribed to such terms in the Merger Agreement.

WHEREAS, Acquirer was formed on August 28, 2024 for the sole purpose of the merger of Parent with and into Acquirer, in which Acquirer will be the surviving entity;

鉴于，Merger Sub于2024年7月10日成立，其唯一目的为与公司合并，使公司成为Acquirer的存续实体，并成为Acquirer的全资子公司；

鉴于，根据变速器协议，Acquirer和Merger Sub需要签署并交付本加入协议； 7.6条项允许的投资 鉴于，本协议各方希望根据本加入协议签署本加入协议，使Acquirer和Merger Sub各自成为变速器协议的一方；

鉴于，本协议各方希望仅修改变速器协议中明确列出的那些条款；

现以前述互相承诺及其他有价值的考虑作为条件，就本加入协议各方一致同意如下：

合约约束

1. 合约约束收购方和并购子公司均同意，在签署本加入协议书后，即成为并购协议的一方，并将完全受并购协议的所有条款、条件、陈述、保证、权利、义务和条件约束，如同原始缔约方一样。母公司和公司均同意此加入及导致并购协议的修订。

2. 继承人及受让人本加入协议书应对当事方及其各自的继受人和受让人具有约束力。

3. 整个协议本加入协议书代表当事方就本主题之间的整个协议，除非本加入协议书或并购协议中明确规定，否则据此解除所有先前就该主题进行的谈判、陈述或协议，无论口头或书面。

4. 对照合约本加入协议书可以分开以副本形式签署，每一份副本均为正本，全部副本一起构成同一协议。本加入协议书可以通过传真或电子传输方式签署和交付。

5. 管辖法 . This Joinder Agreement and any claim, controversy or dispute arising under or related to this Joinder Agreement shall be governed by and construed in accordance with the laws of the State of Delaware applicable to contracts made and to be performed wholly within such State (including in respect of the statute of limitations or other limitations period applicable hereto), and without regard to the conflicts of laws principles thereof. Any dispute relating to this Agreement shall be resolved in accordance with the Dispute Resolution provisions set forth in Section 12.8 of the Merger Agreement.

6. 标题. The headings contained in this Joinder Agreement are for convenience of reference only and shall not be deemed to alter or affect any provision hereof.

[以下为签名页面]

IN WITNESS WHEREOF, the parties hereto have caused this Joinder Agreement to be effective as of the date first written above.