The Captain Patellar Tendon Strap is designed to provide compression on the patellar tendon to relieve discomfort and reduce inflammation. A small rubber cylinder, enclosed within a soft, non-slip surface molds to your lower knee to provide comfortable compression under the knee providing patella stabilization. The adjustable Patellar Tendon Strap is made of soft, flexible neoprene, equipped with a strong Velcro closure, and tapered behind the knee to ensure a comfortable fit during your athletic activities. Designed to be worn on either knee. Benefits: Provides compression on the patellar tendon to help stabilize the patella, relieve discomfort and reduce inflammation. Equipped with a strong Velcro closure for customizable support. Tapered behind the knee for a comfortable contoured fit. Easily adjustable for customized support. Designed to be worn on the left or right knee. 4 size options available. Sizes: Small: 10" - 12" Medium: 12" - 13.5" Large: 13.5" - 15.5" X-Large: 15.5" - 17.5" (Measure the circumference of your knee directly below your knee cap for sizing.)