Size: Diameter 70mm, Height 18mm Color: Green+blue+orange Specifications: 30 pounds, 40 pounds, 50 pounds Material: Silicone Package content: 3 grip rings 1. Strengthens grip and improves dexterity: Hand trainer strengthens your fingers, hands, wrists, and forearms. Hand gripper can be used in various activities including squeezing, pinching, and stretching, which can improve finger and hand dexterity. 2. 3x hand trainers: Hand trainers offer three different resistance levels (30, 40, 50 lbs) to strengthen the hands, wrists, and forearms. Ideal for musicians such as guitar and violin players, climbing, tennis, bodybuilding, golf, and more. 3. Ergonomic design: The size is suitable for adult hands. Perfect size for grip training for men and women. 4. Durable and anti-slip: The grip power amplifier is made of high-quality silicone material, which is odorless and latex-free. It is also lightweight. The anti-slip rings are tear-resistant for long-term use. 5. Portable design: The grip power amplifier is very small and easy to carry, fitting perfectly in your sports bag or handbag. You can perform repetitions while commuting, in the office, or anywhere else.