Provides protection and support for the elbow. Useful in the treatment of tennis (lateral epicondylitis) and golfer's (medial epicondylitis) elbow. Thermoskin increases elasticity of muscles tendons and ligaments to reduce the risk of injury when under stress and strain. Clinically proven to increase surface skin and subcutaneous temperature between 2-3 degrees F the optimal level to make tendons and muscles more pliable and elastic to provide optimal muscle function. The patented Trioxon lining is a series of soft spirals that stimulate the skin to help create heat required for healing. The small fibers in Trioxon lift moisture away from the skin while the knitting process holds air inside the pile to allow the skin to ventilate. The Trioxon lining creates a micro climate that allows your skin to ventilate and remain well oxygenated for hours of continuously comfortable wear. Measure around elbow with arm extended. Small 9 -10.25 inches, Medium 10.5 -11.75 inches, Large 12 -13.75 inches, and X-Large 14 -15.75 inches.