... ,Medium,Firm; Uesd for hand exercising. Item: Hand grip/power grip ball exercise ball1.Material:eco-friendly TPR;2.Different ... grip strengths-Very soft,Soft,Medium,Firm;3.Different ... finger exercising. 4.Our factory is located in Shanghai,China. Pls contact me any time if you have any ... welcome to our company for a visit .. Hand grip ball exercise ball