Provides warmth, compression and knee joint stability. Neoprene wrap is open behind the knee for greater comfort. Unique design offers a smaller, second layer of neoprene to provide custom fit and allow user to control amount of compression. Spiral stays and infrapatellar buttress provide additional support. Made from Neoprene, Velcro, Spiral Stays, Cool Max mesh. If measurements are between sizes, go with larger size.