Aircast AirSelect Short Walking Boot, X-Small. The Short has a durable, semi-rigid shell that helps support the limb while providing protection. The pre-inflated front panel and two adjustable distal aircells, housed within the shell, provide compression and support. SoftStrike technology absorbs and dissipates shock, while the light weight and lab-tested rocker sole combine to encourage a natural gait and a continuation of everyday activities. Customizable, independent aircells. Non-marking, skid resistant rubber tread. Three-strap system evenly disperses pressure, eliminates pooling of edema. Shell: Polypropylene Front Panel: High Density Polyethylene Straps: Nylon Inflation Pumps: Thermoplastic Polyurethane Liner: Nylon/Polyurethane/Polyester (Outer/Foam/Inner mesh) Binding: POLYESTER Outer Sole/Insole: EVA/Rubber. UOM: 1/EA.