The MegaTray. Wheelchair tray provides the maximum in durability and resilience. Constructed from 3/8" polycarbonate material, the MegaTray can withstand anything that a wheelchair user dishes out! The fused bottom-up design, which leaves the transparent surface flush from mounting screws or hardware, is also optimal for sanitation and ease of use. 2 sizes available. Std. Adult (23 1/2"W x 22"D), cutout(15 1/2"W x 10"D). Std. Pediatric (19 1/2"W x 18"D), cutout (11 1/2"W x 7"D).