The ATB-Ultimate is a rough terrain sport wheelchair designed for use by individuals with mobility disabilities or spinal cord injury. FRAME (LxW): 16 x 16 inches magnesium alloy powder coat frame. Frogs Legs rear elastic-polymer suspension is standard. The rear axel center of gravity is adjustable. The frame also had an adjustable angle push bar and custom cut aluminum side guards. SEAT (WxD): 14, 15, 16, 17 or 18 x 14, 15, 16, 17 or 18 inches. Backrest height is available from 8 to 20 inches in 1-inch increments. The backrest angle is adjustable from 90 to 100 degrees. UPHOLSTERY: Laminated carbon fiber sailcloth adjustable by tension cord. BRAKES: Avid Juicy Ultimate hydraulic disc brakes on ADI quick release mounts. CASTERS: 12.5-inch diameter, 2.25-inch wide casters. WHEELS: Spinergy SLX wheels, 25 inches in diameter, with silver anodized handrims. Schwalbe Nobby Nic tires are standard. Six degrees of camber is standard. FOOTRESTS: Single-piece footrest; footplate with toe guard. WEIGHT: 37 pounds. WARRANTY: Lifetime limited warranty on frame.