Strengthens grip, wrist, and forearms. Simply twist the resistance level up or down tubes adjustable spring tension mechanism. Textured rubber handles provide comfort and grip. The hand gripper has been developed for anyone who wants to take their grip strength to the next level.These high quality adjustable spring hand-grippers are crafted so that you can train your grip similar to training any other body part-- by increasing resistance. If you want to develop serious hand strength for a sport, or just want to impress your friends, than these hand grippers are the perfect choice for you!