Rolin Adjust Super Vise Gripper Hand Grip Strengthener 84 points of adjustment will insure a strong grip and forearm growth (as long as you use it). Heavy Knurled aluminum handles for a stable grip.Included chart depicts 2,3 and 4 springs, you can add the more spring to add to your resistance. 2,3 or 4 Heavy Duty Springs for building a crushing grip and massive forearms. 45 - 500+ lbs. of pressure, student,men,women can be use it, for all of members from your family. The Item shiped from US, you will be recieved about 1 week.100% Money Back Guarantee! If for whatever reason you are not happy with our product, we will give a full refund no question asked.