Gosear Gyro Wrist Arm Muscle Force Power Exercise Strengthen Massage Ball Trainer Random Color Quantity One The LED power gyro wrist ball is a new-design sports apparatus, its rotating speed can reach 8000r/min Inner magnetic slices will generate irregular rotating magnetic field matched with convex points outside and stimulate acupoints of hand When it rotates with high speed, the convex points of the ball will massage hands or other parts of body This unique gyro exerciser helps build upper body strength, particularly grip, wrist, upper and lower arm strength, as well as sharpening co-ordination skills. A Fun Way To Strengthen Your Arms &amp;amp; Wrists, remove fatigue