Wirst sports crazy ball Wrist ball with NEON&counter Increase strength of fingers ... like a gyroscope. It is powered by rotating the wrist. The speed of rotation can reach over 12, ... , tennis, squash, cricket, badminton, baseball, bowling, basket-ball,, motocross, mountain climbing.2. Increases strength in fingers, wrists ... not easy to be broken fitness exercise wrist exercise ball with light and counter