abcGoodefg 3 Grip Hand Forearm Strength Gripper FULL SET of all 3 weights Exerciser Gym . Material: environmental protection silicone. . Brand new and high quality. Outside Diameter:6.8cm, Inside Diameter: 3.2cm. Small ones that Easy to use and carry for you. . Increase Your Hand Strength, Pinch Strength and Crush Strength or Regain Lost Hand Strength Due to Ailments or Injury. . An extremely effective finger-hand-forearm strength and endurance trainer. . Fit Grips on the other hand are not stable when squeezed. Extra muscle fibers must be recruited to keep them straight. The result is increased hand strength and hand efficiency that cannot be obtained with an ordinary grip.