1 - TRANSLATION - VS/PC (Q-CON) 016/2018 May 10th , 2018. Attention Managing Director The Stock Exchange of Thailand Subject : Management Discussion and Analysis the first quarter ended 31 March 2018

1 - TRANSLATION - KT/PB (Q-Con) 001/2020 February 13, 2020. Attention Managing Director The Stock Exchange of Thailand Subject : Management Discussion and Analysis for year 2019 Quality Construction

15 May 2017 Subject: Management Discussion & Analysis for Quarter 1 ending 31 March 2017 To: The President The Stock Exchange of Thailand Harn Engineering Solutions Public Company (“The Company

November 28, 2005 No. 10 /2017 August 9, 2017 President The Stock Exchange of Thailand 62 Ratchadapisek Road, Klongtoey, Bangkok 10110 Subject : Clarification of the operating result. Dear sir, We

ที่ BCH No. BCH.174/2017 15 August 2017 Subject : Explanation of the change in operating results of Q2/2017 which exceed 20% To : The President The Stock Exchange of Thailand Bangkok Chain Hospital

ที่ BCH No. BCH.211/2017 8 November 2017 Subject : Explanation of the change in operating results of Q3/2017 which exceed 20% To : The President The Stock Exchange of Thailand Bangkok Chain Hospital

10 November 2017 Subject: Management Discussion & Analysis for 3th quarter ending 30 September 2017 (Rev1) To: The President The Stock Exchange of Thailand Harn Engineering Solutions Public Company

November 28, 2005 No. 13 /2017 November 13, 2017 President The Stock Exchange of Thailand 93 Ratchadapisek Road, Dindaeng, Bangkok 10400 Subject : Clarification of the operating result. Dear sir, We

February 22, 2018 SET-18-AC-001 Dear The President The Stock Exchange of Thailand Subject: Clarification of Result’s Operation for the year ended 31 December 2017 According to the resolution of BKD’s

ที่ BCH No. BCH 018/2018 26 February 2018 Subject : Explanation of the changes in operating results for the year ended 31 December 2017 which exceed 20% To : The President The Stock Exchange of