Power Putty is the most versatile hand exerciser there is to develop strong hands. It is made of a unique silicone rubber that resists in proportion to the pressure applied against it. For example, under hard impact it bounces like rubber, under slow force it stretches like elastic. Squeezing, pulling, stretching, and pinching the putty will strengthen the muscles of the fingers, hand, wrist, and forearm. Power Putty is recognized by golfers, ball players, water skiers, and rock climbers as one of the most effective ways to develop superior hand strength and endurance.