The Patellavator Knee Orthosis has a unique design that applies variable pressure to the patellar fossa tendon without creating a tourniquet around the leg or irritating the popliteal. This is achieved by having an interlocking base strap made of Coolflex material which is very comfortable and flexes with the knee. Offers a low profile design that eliminates irritation to the opposite leg, and allows you to wear the brace underneath your clothing.