The retractable QD-4 comes with a unique locking system that allows quick deployment and a positive lock. Extend it to the desired length and it is ready to use. The minimum extension is 31 ½" for pediatrics, and the maximum extension is 54 ¾" for adults. Features include a low profile "Hare-Type" ischial pad, 4" x 3" wide adjustment elastic straps, and an integral folding heel rest. The ankle hitch is impregnated with antibacterial, antimicrobial Staphcheck materials. Deluxe ratchet system for easy tensioning and release. The unit comes with a heavy-duty nylon carrying case. Meets industry standards. 3 year warranty.