Product details:

The Gyro Grip Strength Toner works the arms and upper body with the power of centrifugal force. Instead of bulky, cumbersome free weights, it has a 1-lb. internal weight that you spin at up to 350 RPM. The faster it spins, the harder the workout. Simply hold it in different positions to isolate and target the forearms, upper arms, shoulders, biceps, triceps, back, chest, core and other areas. Includes digital workout monitor.