Who would have though a simple ball could give your hands, wrists and forearms such a powerful workout?The Magic Power Ball uses the power of the gyro to build strength and endurance as it spins. You'll experience the power of the gyro as it strengthens and stimulates, building your endurance. Simply spin the inner ball, and twist your wrist to get the gyro spinning. The longer and faster you can make it spin, the better the workout. If you use your hands professionally, or suffer from arthritis or carpal tunnel syndrome, this is true therapeutic treatmentGreat for athletes, musicians or anyone else who use their hands professionally, the Magic Power Ball works to strengthen the hands and fingers--especially those who suffer from arthritis or carpal tunnel syndrome. In addition to being a great workout, the Magic Power Ball is fun and entertaining to use. Color may vary.