Features： 1、Exercise your fingers and arm strength. Hold the ball in your hand and pinch it hard so that you can feel the pressure brought by the ball. 2、Generally continue to hold many times, you can feel the palm numbness and fever, and then it is very comfortable feeling. 3、Palm loose and tight movement to hold the ball, and the ball deformation fills the palm, can effectively stimulate the major acupoints of the palm. 4、Promote blood circulation, achieve the effect of exercise, muscle training, and fine and rough motor skills. 5、pcs different colored balls with different resistance levels, from soft to hard multi?step exercises. Improves grip strength, hand endurance, and so on. Specification： Item Type: Grip Ball Material: TPR Different colors represent different resistance levels (in order of hardness) : Yellow ＜Orange ＜Red ＜Blue ＜green Training methods: 1. Squeeze the ball with your fingers and thumb to hold, relax and repeat;Apply pressure to the ball with your fingertips. 2. Keep the ball in the palm of your hand, between your thumb and fingers.Pinch your thumb and fingers together.Hold and relax your hands.Repeat. 3. Squeeze the ball between thumb and index finger together, hold and relax. Repeat 4. Hold the ball between thumb and forefinger, then gently squeeze, hold and release. 5. Put the ball on the table, put your fingertips on the ball, and roll the ball onto the table. 6. With the same hand, place the ball between the bent thumb and index finger, roll the ball, and extend and straighten the thumb.Repeat. Function: exercise knuckle, palm muscle, finger pressing, activating joint Applicable people: climbers, fitness training finger strength and grip strength; Fans of badminton, table tennis, basketball and other ball games; Learn to play the piano to exercise finger strength; People use computer keyboard and mouse for a long time. Package List： 1 x Yellow Ball 1 x Orange Ball 1 x Red Ball 1 x Blue Ball 1 x Green Ball