Our advantage: Soft tip design, which increases comfort and training effect, Optimal for rehabilitation exercise, hand strengthening. You can put the rope around your wrist to prevent the massage ball from slipping during exercise. 2 DIFFERENCES: The grip ball has 2 ranges, 2.3 kg/5 lbs for relaxation and beginners, 4.5 kg/10 lbs for grip training and rehabilitation , you can train alone or involve your family and friends in training. Good Quality: The grip balls are made of high quality rubber (TPR) and will keep their shape even with frequent use . all fingers can be exercised at the same time, durable and safe. Can be rinsed with water after use. Gift Choice: The hand muscle trainer is lightweight and easy to carry, a good choice for preventing strain and relieving pressure. WARRANTY AGE 3: We're so confident you'll get help from this hand exercise ball, what are you waiting for?