Gyroscope Power Wrist Ball Arm Hand Muscle Force Power Exercise Strengthener Ball Trainer Fitness EquipmentHow to use: 1, holding the wrist ball with one hand, the opening part of the upward, the other hand will be the head of the rope into the hole in the center of the ball. 2, with the thumb of the hand holding the ball, turn the ball forward, the rope tightly wrapped around the center of the ball in the center groove. 3, when the rope around the center of the ball half a circle, stop turning the ball center. Use one hand to hold the ball, the other hand