DescriptionGrip strengthen balls, made of silicon environmental material without pollution, and touch comfortable, with a string, easy to carry. Exercise and strengthen hands, fingers, wrists strength so that relieve stress and muscle tension from computer work. String design make it not easy to loss and run away.Features- Color: Blue. - Material: Silicone. - Size: About 5.3x5.3x5.3cm. - Grip strengthen balls, help to decompress yourself after working or study for long time. - With a high elasticity string, avoid slipping out and easy to carry out. - Exercise and strengthen hands, fingers, wrists strength so that relieve stress and muscle tension. - Prevents stiffness, increases flexibility, and reduces joint pain. - Suitable for people of all ages. Easy to carry for outdoor use.