Wirst sports crazy ball Wrist ball with NEON&counter Increase strength of fingers,wrists ... It is powered by rotating the wrist. The speed of rotation can reach over 12,000 RPM.TheoryLike ... golf, tennis, squash, cricket, badminton, baseball, bowling, basket-ball,, motocross, mountain climbing.2. Increases strength in fingers, wrists ... be broken fitness exercise wrist exercise ball with light and counter