Product Description:Color:BlackMaterial:ABS+MetalPackage Includes:1*PliersDescription:MULTI-APPLICATION: This 4-button finger trainer was specially developed for many musical instruments such as the guitar and trumpet. It also helps in your finger strength training. ADJUSTABLE TENSION FORCE: Individual finger tension is adjustable from 3-8.5 lbs. You can lock 2 buttons at the same time, so you can choose different tension strength for each finger and choose which fingers you want to exercise as you like. UNIQUE AND HIGH PERFORMANCE: Environmentally friendly silicone provides good grip during training and copper core spring provides good resistance for strength training. COMFORTABLE GRIP: Non-slip granules on the silicone surface make it not easy to slip from the palm. Grooved button design allows for comfortable pressing. VERY PORTABLE: With a portable size, you can carry it in your luggage, bag, wallet, purse, etc. It is convenient for you to strengthen your fingers at any time.