✔It's good for hand, wrists, shoulders, forearms, biceps and warm-up are good. For medial superior tenosynovitis, prevent tendinitis and improve grip strength, reduce pain of moderate tendonitis in wrist movement.✔The wrist ball uses physical machinery. The faster the rotation speed, the brighter the light will be. Wrist power ball toy hand booster, hand exerciser relieve stress --- anti-stress and anxiety, suitable for adolescents, students, and adults.✔Features1. Wrist ball features an extremely practical automatic starting function.2. Variable speed lighting, bright and dazzling.3. Compact and lightweight, portable and easy to store.4. It helps to perfect the fine motor skills you have mastered in non-mainstream arms.5. Help to relieve tension without batteries or power source.✔Specification1.Main material: preferably pc environmental protection material, platinum2.Contains: wrist force ball, special wrist strap3.Uses: exercise wrist strength, relax decompression, relieve fatigue✔How to use:1. Push the thumbs of both hands in the direction of the arrow of the center of the ball until the resistance is large and the center of the ball cannot roll.2. Quickly release the core of the ball with the thumbs of both hands, and turn the ball by the hand3. After feeling the sphere rotates, swing the ball from left to right in a circle-like way to slowly rotate the wrist ball, and the speed can be increased with the inertia✔Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. ✔ Service:1. If you need more styles, please click our other products to find the style you want.2. If you have any questions before or after your purchase, please do not hesitate to contact us.