Product information: Material: silicone Color: yellow, blue, red Size: 53mm Weight: 54 g Strength: Yellow light intensity: approx. 1-10 kg, red: approx. 5-20 kg, blue: approx. 10-40 kg Packing list: 3 * hand trainer finger trainer 1. 3 pieces hand trainer ball Finger trainer hand trainer has 3 different degrees of hardness. The yellow ball is for soft resistance, the red ball is for medium resistance, and the blue ball is for hard resistance. If you want to improve your finger mobility or restore the function of your fingers and forearms due to an illness, you can use our hand trainer set. 2. Washable Hand Training Ball The hand training balls are washable and can be cleaned with water as usual after use. With its oval egg shape, this anti-stress hand ball adapts perfectly to your hand. The surface of the finger trainer is slightly roughened and prevents it from slipping away. 3. Durable and robust Anti stress balls: The ball hand training devices are made of high quality thermoplastic rubber and keep their shape even with frequent use. Our hand exercise balls are uniquely designed for long-term and frequent use. Safe, environmentally friendly and still durable. 4. Anti-stress balls for strengthening Rehabilitation Ball Hand The anti-stress balls support you in addition to training your resilience and the development of dexterity in order to reduce stress. The hand training device is suitable for a wide variety of people and is particularly suitable for sports and activities such as climbing, bodybuilding, fitness, tennis, baseball, boxing, golf, etc.