I just saw this show up on a Facebook post, and it's got an article on Teslarati. Martin Brower has also been doing some evaluation usage with two Tesla semis. They seem to be a supply distributor that works mostly with restaurant chains.
Tesla Semi pilot expands to Martin Brower
Tesla Semi executive Dan Priestley noted that Martin Brower (MB) has also started a pilot program for the Class 8 all-electric truck
www.teslarati.com