Features： 1、Exercise palm muscles and finger flexibility, suitable for primary strength training and rehabilitation training. 2、The ball can effectively stimulate the various parts of the palm, promote blood circulation, and achieve the effect of exercise and fitness. 3、Using durable high?elastic materials, elastic and not deformed, small size, convenient to carry. 4、Bright color and flexible hand feelings makes the grip ball suitable for all ages. 5、Designed for piano learner, rock climbers and bodybuilders, etc. to train fingers and grip. Specification： Item Type: Hand Grip Ball Size: Approx. 80 x 80 x 30mm / 3.1 x 3.1 x 1.2in Different Colors Represent Different Strengths: Yellow<Orange<Pink<Blue<Green Suitable Crowd: Rock climbers and bodybuilders train finger strength and grip strength; lovers of ball sports such as badminton, table tennis, and basketball; learn to play the piano to exercise finger strength; for people who use computer keyboards and mouse operations for a long time. Basic Exercise: Hold the grip ball completely in your palm, and do ten hand stretching exercises, first doing right hand exercises and then left hand exercises, alternate exercises. Package List： 1 x Hand Grip Ball