Product Size: 58*44mmColor: blue (gravity) + yellow + red, black + red + greenMaterial: TPEPackage content: 3* grip ball1.MAKE EXERCISE SIMPLE These colorful stress relief balls in three levels of progression can improve finger and grip strength for athletes (rock climbing enthusiasts, fitness, tennis, baseball, boxing, tennis, golf and shooting) and musicians (guitar players, bass players, pianists and violinists). It can also relieve some of the tension and anxiety.2.REHABILITATION & PREVENTION Your hands probably will get quite sore from using a keyboard and mouse all day and exercising your hands with these egg shape hand therapy balls can definitely solve the issue It is perfect for your arthritic hands, to build strength without causing injury or pain. You can also use these to try to overcome a habit of picking at hangnails and cracking my knuckles.3.USE IT ANYWHERE ANYTIME Our stress relief toys set has a small size and charming egg shape looking. This is a really nice size because you can fit it in your scrub pocket and take it out to squeeze when you need to. You can use it while walking, traveling (car, airplane, bus), in office, school, watching TV, phone calling or any place you want to exercise.4.SAFE AND DURABLE FOR BOTH CHILD & ADULTS The Hand Exercise Eggs are made of a thermoplastic rubber , but do not have a strong rubbery odor and are washable in plain water. Completely safe for kids and adults. You might find the egg gets a little bits of sand and lint when it falls into the floor, never mind, it is very easy to be cleaned by washing it under water.5.MUSCLE TRAINING: the hand press ball allows for strengthening exercises of the hand muscles, finger muscles as well as the forearm stretching muscles. The egg-shaped design and textured surface of the hand muscle trainers make them very easy to grip. For large hands, we recommend the XL grip balls from our other range.