Adjustable locking straps together with a metal splint positioned at 25° to provide the protection and support needed for treating Carpal Tunnel Syndrome. Increases circulation to aid in the treatment of repetitive stress injuries (RSI) and tendonitis. The built in adjustable Thumb Spica provides protection and support to the thumb and ulnar collateral ligament. The Thermoskin Wrist Brace with Thumb Spica offers the added benefit of heat therapy. SIZING GUIDE: Measure circumference around wrist joint. XS/Small for 4 ½ - 6 ¼ inches. Medium for 6 ½ - 7 ½. Large/XL for 7 ¾ - 10 inches.