Chinese Baoding Healthy Balls stimulate and exercise your hands muscles by moving both of them in one hand. The balls are metal, brilliant painting and design, hollow and have chiming sounding plates inside. They make crisp and rhythmical sounds when moving.Play them to relax and reduce stress. Beautiful silk covered box and instructions included. Additional Details ------------------------------ Product description: Chinese Baoding Healthy Balls stimulate and exercise your hands muscles by moving both of them in one hand. The balls are metal, brilliant painting and design, hollow and have chiming sounding plates inside. They make crisp and rhythmical sounds when moving.Play them to relax and reduce stress. Beautiful silk covered box and instructions included.