The Captain Knee Sleeve with Patella Stabilizer is anatomically designed to provide mid-level support without limiting range of motion. The padded patella stabilizer ring reduces unnecessary patella movement associated with many knee injuries and the comfortable compression keeps the knee warm and loose to reduce the likelihood of injury. The Captain Knee Sleeve with Patella Stabilizer is made from lightweight, breathable neoprene with reinforced upper and lower seams for lasting durability. Benefits: Anatomically designed for added comfort. Built-in padded patella stabilizer ring. Reinforced for lasting durability. May be worn on either the left or right knee. 4 size options available. Sizes: Small: 11" - 13.5" Medium: 13.5" - 15" Large: 15" - 16.5" X-Large: 16.5" - 18" (Measure the circumference of your knee directly over the joint for sizing.)