Ref. No. IVL 004/02/2020 26 February 2020 The President The Stock Exchange of Thailand Subject: Submission of Annual Audited Financial Statements and the Management Discussion and Analysis of

operating results for the 3-month period and 6-month period ending June 30, 2017 To : President The Stock Exchange of Thailand Diamond Building Products Public Company Limited and its Subsidiary (together

Ref. DBP. 141 / 2017 November 13, 2017 Subject : Clarification on Operating Results for the 3-Month Period and 9-Month Period ending September 30, 2017 To : President The Stock Exchange of Thailand

the director of the company and member of the Audit Committee To Director and Manager The Stock Exchange of Thailand Reference is made to the resolutions of the Board of Director Meeting No. 3/2019 of

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

Ref. No. IVL 005/11/2019 11 November 2019 The President The Stock Exchange of Thailand Subject: Submission of Quarterly Review of Financial Statements and the Management Discussion and Analysis of

Ref. No. IVL 002/05/2020 12 May 2020 The President The Stock Exchange of Thailand Subject: Submission of Quarterly Review of Financial Statements and the Management Discussion and Analysis of

July 2009 shall be repealed. Clause 3 In this Notification: “asset” means land, structure, machinery, equipment, long-term lease, patent or intellectual property being eligible to be assessed under

/2019 (additional) To Director and Manager The Stock Exchange of Thailand Enclosure 1. Information Memorandum on the Acquisition of Assets (Schedule 1) Regarding the Purchase of the Ordinary Shares of KPN