... rotating the wrist. The speed of rotation can reach over 12,000 RPM.TheoryLike gyroscopes.centrifugal force and inertia are applied ... sports like golf, tennis, squash, cricket, badminton, baseball, bowling, basket-ball,, motocross, mountain climbing.2. Increases strength in fingers, wrists, hands ... is not easy to be broken fitness exercise wrist exercise ball with light and counter