... 1,PP comfortable handles; 2,spring. 3,NBR foam 4,develop muscles in wrists and forearms 1,PP ... comfortable handles; 2,spring. 3,NBR foam 3,develop muscles in wrists and forearms Our factory,Jiangsu ... Ltd is a famous factory for exercise accessories such as1.hand grip / jump rope2.Expander3.Push up bar/thigh master4 ... .Aerobic step9.ankle wrist weight/training vest10.support hand grip