Features: 1Durable Material: Grip ball is made of non slip PU with concave and convex surface, which is comfortable, easy to hold and can be used for a long time. 2Training Center: Grip balls will focus more on finger grip, emphasizing full hand coordination, including thumbs and training your forearm and grip. 3Adjustable Weights: You can choose to add different weight plates (2.5 lbs to 200 lbs) to the tray to start your grip workout and improve strength, power and grip. You can start slowly with lighter weights. 4Applicable People: Suitable for everyone, including beginners, musicians, athletes, golfers, rock climbers and tennis players. Perfect for people who have arthritis, help for recovery. 5Solid Ball: For wrist strengthening, ideal for wrist, hand and finger strength training. Improve your hand, finger, wrist and forearm strength. Package included: 1 x Grips&nbspBall 1 x Buckle Tray