The Gripmaster Pro Hand Exerciser is a tool used to strengthen the muscles within the hand and most muscles and tendons in the forearm. There are three levels of tension available medium tension (7lbs. per finger), heavy tension (9lbs. per finger), and extra heavy tension (11lbs. per finger). Gripmaster Pro Hand Exerciser is portable and easy to use. Used by professional sports trainers for an effective isolated resistance workout which develops and maintains strength, hand control, endurance, coordination, and dexterity. Purchase your Gripmaster Pro today!