Product Description Size: 9*8*2.5cm Material: ABS Package content: 4* gripper 1.Main function: our finger strengtheners are designed to develop and maintain the strength and dexterity of your fingers, hands, and forearms. 2.Ergonomic design: these hand exercisers are design with ergonomic palm grip, which will provide you a customized conditioning for individual fingers, the entire hand, wrist, and forearm, secure and comfortable to use 3.Fine workmanship: our finger strengtheners are made of quality plastic and springs, durable enough for you to exercise every individual fingers, as well as your entire hands, suitable for those who need finger power, like athletes, guitarist, pianist, accordion performer, violinist, hand reconstruction patient, etc. 4.High quality finger trainer with a solid structure Finger trainers consist of a high quality, high quality spring, new ABS plastic, , are comfortable to hold and easy to trianen, do not injure your fingers, are durable and have a longer service life than other finger trainers in occupational therapy . 5.Extremely portable design finger trainer piano, easy to carry You can carry it in your luggage, bag, purse , purse, etc. The slim size allows you to hold everything in the palm of your hand and make it portable for exercising your fingers whenever you want.