Product Description Size: diameter 7.8cm, thickness 2.2cm Color: yellow, rose red, blue, green, orange, black Material: Silicone Package content: 6* gripper 1.STRENGTHENS GRIP AND IMPROVES DEXTERITY: Hand exercise rings build 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. 2.PROGRESSIVE RESISTANCE LEVELS: Progressive levels of resistance allows the difficulty of each workout to be gradually increased as your grip improves. The color coded set includes 30 lb. 40 lb, 50 lb, 60 lb70lb,80lb, rings which can also be used for effective interval training, alternating between the three resistance levels in a single workout. 3.PERFECTLY SIZED FOR A COMFORTABLE FIT: Sized to comfortably fit adult hands with an outer diameter 7.8cm, thickness 2.2cm. Perfectly sized for grip strength training for both men and women. 4.DURABLE NONSLIP SILICONE CONSTRUCTION: Hand grip strengtheners are constructed with a premium silicone material that is odorless and latex free. The nonslip rings are also tear and crack resistant for long-term use. 5.Portable Grip sneakers with nylon travel bag, small and light, easy to put in pocket or pocket. You can take it with you at home, in the office or anywhere.