It is a type of splint that immobilize thumb. The aliminium atele inside provides stabilization of the thumb. It can adjust with velcro on it for wrist. Indications Lateral injuries of the thumb joint Distortion 1. MCP joint irritation (eg rhizarthrosis) SIZE WRIST CIRCUMFERENCE (RIGHT-LEFT)(cm) S 14-16 M 16-18 L 18-20 XL 20-22 XXL 22-24 Declaration of Conformity CE