This Aluminum Hand Grip series was developed for athletes who want to take their grip strength to the next level. These high-quality hand grips are crafted with 25 and 50 pound torque increments from 100lbs to 350lbs, so that you can train your grip similar to training any other body part; by increasing resistance. They are ideal for developing strength and stamina safely, efficiently and effectively while reducing stress at the same time. Great for strength training, sports training, and rehabilitation.