Stretch, squeeze, pull and pinch Power Putty to strengthen fingers, hands, wrists and forearms for rock climbing and other activities. Power Putty helps develop strength and dexterity. Exercises individual fingers and thumb. Works fingers in a full range of motion from closure to extension. Strengthens all muscles of the fingers, hand, wrist, and forearm. Power Putty hand strengthener is available in 4 resistances: soft, medium/soft, medium/firm and hard