Da Vinci Adjustable Hand Grip Strengthener, Hand Exerciser Resistance Range from 22 to 88 lbs (10-40 KGs) Adjustable hand grip exerciser with resistance level of between 22 to 88 lbs (10 to 40 KGs) Easily adjust resistance level with a simple twist of a dial Comfortable handles and a durable and strong spring that is built to last A fantastic device for athletes to strengthen forearm, fingers, hands, and wrist Recommended by physical therapists and chiropractors