The Heavy Grips&trade hand gripper series was developed for athletes who want to take the training of their grip strength to the next level.

These high quality aluminum-handled hand-grippers are crafted with 50 inch-force-lb torque increments from 100lbs to 350lbs so that you can train your grip similar to training any other bodypart-- by increasing resistance. This will finally allow you to build the huge forearms and crushing grip you have been unable to achieve by doing endless reps with plastic-handled hand-grippers.
Each resistance of the hand grippers correspond to colours.

Hand Grips - Hand Exerciser