These are pull-up , which through building strength in the fingers, hands, wrist and forearms. Varied activities, including crushing, pinching and extensions, work to improve the dexterity of both the fingers and hands. Perfect for athletes, musicians and physical therapy patients. Features - Color: As Shown - Material: Polyester Cotton, Nylon, Steel - Size: About 21.00X3.80X0.30cm/8.25X1.49X0.12inch - Toughness and elastic to create an integrated molding, to provide resistance to grinding power. - With the smooth surface and different strength type, can strengthen hand feeling, anti-slip massage. - Designed in round shape, and palm-size convenient storage, home travel can be played. - Simply wash the stain and make it look new. Suitable for your hand strength training in home and fitness center. - In adoption of the good and , wear resistant and durable for long serving time. Package list: 2 x Balls 2 x Hooks 2 x Ribbons