Hope this helps, the material is 3.2mm thick, hard grey plastic. The boards were shipped with centre boards installed, held in with the two screws. They rairly needed removing for maintenance, it was the track that tended to require more loving.
Not a board to ride without booties, lots of sharp things to hurt your feet. Interestingly, one fail was that Steve didn't fit a towing eye to his race boards, a requirement under class rules, so if you find a board with a towing eye, it has been raced.