Hand Exerciser Set is an ideal training set to improve the overall grip strength, improve the flexibility of fingers, avoid stiffness, relieve joint pain while promoting blood circulation in the hand, and prevent an imbalance of the muscles of a single finger due to excessive use Hand stress ball is suitable for a wide range of population, is especially useful in the following sports and activities: love climbing, bodybuilding, fitness, tennis, baseball, boxing, golf and shooting, etc. Also perfect for PC users (programmers, writers, students), musical instrument players (guitarists, bassists, pianists and violinists) Put the hand trainer grip balls in the refrigerator for about 40 minutes, then you can enjoy the cold therapy; the finger holes on the finger stretcher are not very large, but elastic. If you carry the finger stretcher with the help of the other hand, it is easier to do that Hand Strengthener made of 100% food grade soft silicone, safe, environmentally friendly and still durable