AC2802/2018 February 28, 2018 Subject: Management Discussion and Analysis for Year2017 To: Managing Director The Stock Exchange of Thailand The company would like to report the operation results for

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

1 - TRANSLATION - VS/PC (Q-CON) 026/2018 August 06th , 2018. Attention Director and Managing Director The Stock Exchange of Thailand Subject : Management Discussion and Analysis the second quarter

1 - TRANSLATION - KT/KP (Q-CON) 007/2018 November 1st , 2018. Attention Managing Director The Stock Exchange of Thailand Subject : Management Discussion and Analysis the third quarter ended 30

1 - TRANSLATION - KT/PB (Q-Con) 004/2019 February 4,2019. Attention Managing Director The Stock Exchange of Thailand Subject : Management Discussion and Analysis for year 2018 Quality Construction

1 - TRANSLATION - KT/PB (Q-Con) 025/2019 November 1, 2019. Attention Managing Director The Stock Exchange of Thailand Subject : Management Discussion and Analysis the third quarter ended 30 September

จดหมายชี้แจงq363e November 13, 2020 Managing Director Stock Exchange of Thailand Subject : Management Discussion and Analysis for three month Ending 30 September 2020 Summary onThird Quarter result

จดหมายชี้แจงq263e August 13, 2020 Managing Director Stock Exchange of Thailand Subject : Management Discussion and Analysis for three month Ending 30 June 2020 Summary on Second Quarter result

ACC1/20-012 February 25, 2020 Subject: Management Discussion and Analysis for the year ended December 31, 2019 To: Director and Managing Director The Stock Exchange of Thailand Qualitech Public