... appointed forwarder Usage: mainly for sports like tennis, golf, basket-ball, table tennis, badminton, bowling, rowing, rock-climbing ,basketball, motocross, mountain ... ,000 RPMBuilt-in glaring LED light. Once this powerball is activated, it starts to glow BLUE. The faster the unit runs ... and to keep in sync with the spinning of the ball. Roller ball doesn't need batteries, is only slightly bigger than ...