Increase endurance, decrease arm fatigue and strengthen your grip with the The Dynaflex X-Grip Pro hand exerciser. Gyro mechanism replaces traditional weights to tone and strengthen shoulders, biceps, triceps, forearms, wrists and hands. Variable resistance is achieved by increasing or decreasing the speed therapeutic for hands, wrists, arms, biceps and triceps. Aids in the prevention of repetitive stress injuries such as carpal tunnel syndrome. Get the edge in rock climbing and any other sport that requires control and a strong grip. Generates up to 40 lbs. of gyroscopic pressure when maximum RPMs 13,000 are reached.