MobileSharp30LB Silicone Hand Grip Strengthener Resistance Exercise Rings - Physical Therapy & Stress Relief for Youths, Children, Computer Users & Gamers - plus Muscle Rehabilitation after Strokes Fit for men and women. Can develop serious hand strength, hand grippers is the perfect choice for you . Sized especially for adult hands, to maximize the benefits of the exercise and ensure a challenging, yet safe experience. Material--The grippers are made from premium silicone, the high quality item can strenghten your muscle. These rings are great for training athletes, and giving their performance a positive boost . Will build hand and forearm strength for added performance in any sport anytime, anywhere. Ideal gift choice for your friends.