Features: Brand China's traditional hand exercise equipment has a history of thousands of years. The method of use is very simple: place 2 or more iron balls in your hand and rotate them. The surface is enamel, hollow in the middle, and produces a ringing sound when spun. Helps maintain hand, finger, wrist, and arm health. Recommended by hand therapists, using baoding balls can strengthen hands and improve flexibility, supporting management of hand conditions such as arthritis and nerve damage. Additional benefits may include keeping hands occupied to reduce unwanted habits, improving circulation, aiding focus during meditation, enhancing concentration, and more. Satisfaction guaranteed. Please if you have any questions. Thank you! Specifications: Color: As shown in picture Material: Enamel Sales Method: Retail, Wholesale, Drop Shipping Size: One Size Length: 4.7 cm (1.85 in) Width: 4.7 cm (1.85 in) Height: 4.7 cm (1.85 in) Quantity: 1 pair Package Includes: 1 Set Baoding Balls Note: Due to manual measurement, there may be a 02 cm variation, which is normal. Due to differences in monitor displays, the actual item color may vary slightly from the images. Thank you!