Therafin’s Quantum TB3 Steel Channel Bracket is attached to a Therafin half tray that is upholstered with black satin vinyl over 1″ thick foam, on a 1/2″ thick wood base. It’s easy to wipe clean, and all materials are latex free. The bracket slides the tray on from the front, and flips the tray up and out to the side for easy transfer. Bracket fits the TB3 armpad with maximum dimensions of 2-11/16″ wide by 1-1/2″ tall. Trimline shape half trays have a straight outer edge that offers support for people with weakness on one side and allows more belly clearance.