I had 18 ga steel U pans made and cut out squares with a pencil grinder and steel cutting discs. The angled back feet on the sys fit into the squres and catch and the front feet sit down into the holes locking the sys into the shelf. The frame is 8020 quick frame, single fin. The back panel is face screwed to the framing. The panels are .220 black haircell ABS. The cabinet is movable using quick frame three way extrusions with holes for posted wheel sets.