Shareholders will be admitted to the virtual Annual Meeting at www.virtualshareholdermeeting.com/MTX2020 by entering the 16-digit control number that can be found on their proxy card or voting instruction form previously distributed. Shareholders may log in to the meeting platform beginning at 8:45 a.m. ET on May 13, 2020. Shareholders will have the opportunity to vote their shares and ask questions at the Annual Meeting using the instructions provided on the meeting website. Those without a control number may attend the Annual Meeting as guests by logging in to the same virtual meeting platform and following the instructions on the website for guest access. Guests will not be able to vote or ask questions.