Stock Exchange of Thailand Enclosure: 1. Information Memorandum Re: Acquisition of Assets of T.K.S. Technologies Public Company Limited (Schedule 1) 2. Information Memorandum Re: the Allocation of the

Shareholders in Proportion to their Respective Shareholdings and Convening of the Extraordinary General Meeting of Shareholders No. 1/2018 (Second Amendment) To: President The Stock Exchange of Thailand

to investors in private placement, the acquisition of assets and convening the Extraordinary General Meeting of the Shareholders No. 1/2018 (Revise 2) To : President, The Stock Exchange of Thailand

Amount and Term of Bond Issuance, and Determination of Date of the Extraordinary General Meeting of Shareholders No.1/2018 To: The President of the Stock Exchange of Thailand Enclosure: 1. Capital Increase

Amount and Term of Bond Issuance, and Determination of Date of the Extraordinary General Meeting of Shareholders No.1/2018 (Revised No.2) To: The President of the Stock Exchange of Thailand Enclosure: 1

Amount and Term of Bond Issuance, and Determination of Date of the Extraordinary General Meeting of Shareholders No.1/2018 (Revised No.3) To: The President of the Stock Exchange of Thailand Enclosure: 1

is selected to include in Thailand Sustainability Investment (THSI) among other 65 listed companies by the Stock of Exchange of Thailand (SET). This selection does not only reflect how the company

ที่ กตพ Ref. DBP. 108 / 2019 August 13, 2019 Subject : Clarification on Operating Results for the 2nd quarter and 6-month Period ending June 30, 2019 To : President The Stock Exchange of Thailand

Ref. DBP. 153 / 2019 November 11, 2019 Subject : Clarification on Operating Results for the 3rd quarter and 9-month Period ending September 30, 2019 To : President The Stock Exchange of Thailand

registration statement has been registered by the Office of Securities and Exchange Commission. The effectiveness of this registration statement neither represent that the Securities and Exchange Commission, the