Ergonomic design: The shape of the soccer ball with four finger holes is more in line with the hand engineering design, easy to hold, the hole diameter is 2.5cm, suitable for outdoor use. 'most adults' finger exerciser Function: It is a grip strength trainer for adults, a physical therapy ball for hand spasms, arthritis and accidents brain vascular, a stress ball for cell phone and computer enthusiasts, and a squeeze ball for people with ADHD. Perfect Design: The grip strengthening ball is a good size and easy to pick up and train. It is ideal for reducing stress in busy or boring life. You can use it while walking, traveling, in the office, at school, watching TV, calling the phone or anywhere you want to exercise. Easy to carryThe finger strength balls are lightweight and you can take them anywhere you want in your bags, suitable for many occasions, such as school, home, office, etc.