The grip specifically designed to isolate the forearm and hand muscles. High quality Steel spring. Strong, durable, unbreakable, not easily damaged. Scientific design, small size and space saving. Small enough to into a pocket, purse, backpack or gym bag. People that play sports and are looking to increase their hand, wrist and forearm strength. The finger grips is a very convenient fitness equipment, while watching TV to exercise, get rid of the boring fitness feeling, easy to train a body.