Description: Material: This hand exercise gripping ring is made of quality TPE material, which is sturdy and and long time use.Function: The strengthener can strengthen wrists, improve the dexterity of your fingers, and increase the strength of your hands. The wrist and finger exerciser is suitable for both men and women, teens and seniors.Wide Application: The hand grip trainer, is great for improving power and flexibility in the wrists, fingers, and forearms.Portable and Lightweight: The ring hand gripper is convenient for training finger at home office, comfortable for you to grip, and easy and convenient to carry. 30LBS, 40LBS, meet different strength requirements at various stages of your training progression.Great Gift: Finger strengthener trainer is a great gift choice for someone who is a sports athlete, golf player, office staffs, pianist, drummer, guitarist, pianist, and much more. Size Chart: 7cm/2.76inch Package Includes: 3 Hand Grip Exerciser Strengthener Note: Please allow slightly errors due to manual measurement and different monitors.