STRENGTHENS GRIP & IMPROVES DEXTERITY: Hand exercise rings strengthen your fingers, hands, wrists, and forearms. Varied activities including squashing, pinching, and extensions work to improve dexterity in both your fingers and hands. Perfect for athletes, musicians, and physical therapy patients. PROGRESSIVE RESISTANCE LEVELS: Progressive resistance levels allow the difficulty of each workout to be gradually increased as your grip improves. The color-coded set includes 40 lb rings that can also be used for effective interval training, alternating between the three resistance levels in a single workout. PERFECT SIZE FOR A COMFORTABLE FIT: Sized to comfortably fit adult hands with a 3.45" outer diameter and 1.75" inner diameter. Perfect size for grip strength training for men and women. DURABLE NON-SLIP SILICONE CONSTRUCTION: The hand grip strengtheners are constructed with premium silicone material that is odorless and latex-free. The non-slip rings are also tear and crack resistant for long-term use.