New thumb extension adds stability and allows for additional pressure on the thumb joint carpal-metacarpal capsule. The thumb extension is proximal to the DIP joint. The glove-like design makes it easy to put on without assistance. Stitching in the web space between the thumb and index finger passively acts like a mild "c" bar to maintain the web space. The basic design encourages a neutral hand position. Repeat application of point pressure on the joint capsule relieves pain by reducing edema. The unique pressure button can be accurately placed to provide pressure exactly where needed. The splint is made from a thick, dense beige neoprene composite that is similar to adding a therapeutic level of force. Nylon-lycra interior. 1-1/2" comfort-stretch strap. Sizing: Measure circumference of the hand over the MP joints at the widest point. Small fits 6" to 6 -7/8" - Medium fits 7" to 7-7/8" - Large fits 8" to 8-7/8" - X-Large fits 9" to 9-7/8"