Strengthens muscles in handLow-powder latex constructionManufacturer's warranty included (see Guarantee & Returns)Size is dependent on resistance level. Often used in hand therapy, the CanDo Web Hand Exercisers Low Powder Latex Hand Therapy Device helps to strengthen your hand muscles. Designed for flexion, extension, opposition, and supination exercises and with a variety of resistance levels available (subject to availability), you'll be able to work continuously towards strengthening your hands. The discs are made from low-powder latex for strength and durability. Size: 14 diam. in..