wrist ball, gyro ball, spin ball, force ball, wrist exercise ball Item: WRIST BALL, TRANSPARENTSHELL MATERIAL: A GRADE PCROLLOER MATERAL: ZINC-ALLOY AND A GRADE ABS FUNCTION:1,Perfect exercise gadget for sports like golf, tennis, squash, cricket, baseball, bowling, basket ball, motocross, mountain climbing.2.Increase strength in fingers, wrists, hands, forearms, biceps, triceps, ligament and ...