Product Size: Diameter 70mm, Height 18mm Color: Green+blue+orange Specifications: 30 pounds, 40 pounds, 50 pounds, Material: Silicone Package content: 3*grip ring 1.Strengthens grip and improve 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. 2.3 x 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, violin, climbing, tennis, bodybuilding, golf, etc. 3.Ergonomic design: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 odourless and latex-free. And are lightweight . The anti-slip rings are also tear and tear resistant for long-term use. 5.Portable design: the grip power amplifier is very small and easy to carry and fits perfectly in your sports bag or handbag. You can install repetitions when commuting, in the office or anywhere else