You can use this baoding ball to exercise your finger for strengthen its power and promote blood circulation by stimulating its acupuncture, which can also relieving your life pressure for massage the uncomfortable parts of your body. Designed with natural stone and smooth surface, which can effectively apply to every age range for easily and conveniently use, to improve flexibility of adult, exercise brain of kids. This baoding ball is made of natural stone material. The diameter of the baoding ball is 5.2cm. It is suitable for skin care and hand massage for gift to friend, colleague, family and elder people. Item Name: Baoding Ball Material: Stone Size Details: Diameter: 5.2cm/2.05" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension differences due to different manual measurements. How to Use: 1.Put two balls in your hand, relying on five fingers flexion and extension, so that the two balls circled with each other. 2.Put tow balls in your hand, then use fingertips to catch it hard and loose it, repeat this step for about 10 times. 3.You can also use this ball to knock and massage the uncomfortable parts of body to achieve fitness effect. Package Includes: 1 Pair of Baoding Ball(2Pcs)