Features： 1、Reduce muscle pain and can help you increase blood flow and tissue hydration, improve athletic performance, increase flexibility. 2、Lighter than ordinary massage ball of the hollow soft ball, better grip feel and comfortable to hold. 3、Can promote the recovery of hand injury and enhance the strength and flexibility of hands and fingers. 4、Soft thorn on the ball surface can stimulate the hand, but will not sting or cause pain feelings. 5、Suitable for training hand muscle and finger flexibility, suitable for primary strength training and rehabilitation training. Specification： Item Type: Grip Ball Material: TPR Diameter: Approx. 7cm / 2.76in Hardness: Hollow soft ball Grip ball, also called pressure ball, stress relief ball, is also a fitness ball. Can exercise hand muscle and finger flexibility, suitable for primary strength training and rehabilitation training. Use method: Basic exercise: hold the ball completely in the palm of your hand and do 10 times hand stretching exercises, first with your right hand and then with your left hand, alternating Applicable people: Climbers and bodybuilders training finger and grip strength Fans of badminton, table tennis, basketball and other ball games Learn to play the piano to exercise finger strength For people use computer keyboard and mouse for a long time Package List： 1 x Grip Ball