K4 Extra-Wide Lightweight Wheelchairs WHEELCHAIR, K4 BASIC, 20", DESK ARM, S-A Swing back arms with easy flip back arm release. Armrests and calf pads are upholstered and padded. Quick release axles allow tool-free removal of rear wheels. Dual axle hemi-height adjustable; Adjustable height back. Tough nylon upholstery. Arm styles available: swing back desk length and swing back height adjustable desk length; Leg style: detachable footrest and detachable elevating footrest. Seat sizes come in: 20" x 18" (51 cm x 46 cm) and 22" x 18" (56 cm x 41 cm).