Description: Durable Material: This hand exercise gripping ring is made of high quality silicone material, which is soft, durable and also eco friendly. Function: The hand grip can accurately record, 120s and 90s countdown, and backlight design, it can strengthen wrists, improve the dexterity of your fingers and increase the strength of your hands. Wide Application: The hand grip trainer, is perfect for improving power and flexibility in the wrists, fingers, and forearms. Portable and Lightweight: The silicone ring hand gripper is convenient for training finger at home office, comfortable for you to grip, and easy and convenient to carry. Compact Size 8cmx8cm/3.15inchx3.15inch. Great Gift: The wrist and finger exerciser is suitable for both men and women, teens and seniors, great gift for families, friends, colleagues, etc. Specification: Material:Silicone Size Chart: 8cmx8cm/3.15inchx3.15inch Package Includes: 1 Hand Grip Exerciser Strengthener Note: Please allow slightly errors due to manual measurement and different monitors.