Bought this during my tour to Beijing China in the 90s. These are Baoding balls, also known as Chinese exercise balls or Chinese health balls. They are used for physical exercise and therapy by rotating them in one hand. Baoding balls are believed to improve finger dexterity, relax the hand, and aid in the recovery of muscle strength and motor skills. The practice dates back to the Ming dynasty. According to traditional Chinese medicine, rotating the balls stimulates acupressure points in the hand, which are connected to the central nervous system and vital organs. The balls often contain chimes that produce a pleasant melody when rotated, which can aid in meditation and stress reduction. PLEASE NOTE: Thank you for looking at my post. I check my emails 1-2 times daily, but may be delayed due to my disabilities, which require me to visit hospital. The exchange must be in-person, with cash, at pre-arranged pick-up at my location. If your out of the area, please have family, friend, or arrange courier service to pick-up on your behalf. Hope to hear from you soon.