Yasco Tennis/Golf Elbow Strap is ideal for using in athletics and occupational activities. It provides relief from painful symptoms of tennis or golf elbow, also meets your performance needs during sports and other physical activities. The outer material is adjustable velcro strap and inner material is neoprene. This design is lightweight and provides durable support for long term wear. Inner perforated neoprene material helps pull moisture away from skin. Ideal support for forearm muscle during motions, preventing muscle injuries or fatigue to ensure maximum performance is reached. The heat retaining function of the neoprene layer can also speed up the muscle recovery period and relieve pain from Carpel Tunnel Syndrome or muscle trains. One size fit most, for elbow size up to 11.5". Caution: Please do not use it if you are allergic to neoprene Wearing instruction is available on Comfytopia official website.