The Actimove Arthritis wrist support features the following: Special ceramic fibers retain and reflect body heat to provide soothing warmth that helps relieve pain. Four-way compression provides light, comfortable support to reduce swelling and improve mobility. Therapeutic heat promotes circulation around the wrist, allowing you to return to your daily activities more quickly. Size S: 12-15cm Size M: 15-17cm Size L: 17-19cm Size XL: 19-21cm