... or your appointed forwarder Usage: mainly for sports like tennis, golf, basket-ball, table tennis, badminton, bowling, rowing, rock-climbing ,basketball, ... makes blood circulation well. Moreover, Powerball helps to prevent tennis elbow, Carpal Tunnel Syndrome and Repetetive Strain Injury (RSI ... t need batteries, is only slightly bigger than a tennis ball and doesn't weigh much more, making it easily ...