About this projectOriginal Spring-Loaded Hand and Finger Exerciser: Used as a rehabilitation tool by professional athletes, world-class musicians. Made of high quality components ABS plastic, stainless steel springs and approved santoprene.Athlete Strength, Strength and Endurance: Work out each finger individually or the entire hand. Isolate and work on strength, flexibility and stamina for each finger individually. Develop excellent hand, wrist and forearm strength.Rehabilitation and Prevention (Stronger, Healthier Hands): Ideal for those who want to develop and maintain strong and healthy hands. May help with arthritis, carpal tunnel, neuropathy and poor circulationVarious Tension Levels: Graded tension levels help users measure progress. VIA 1 lb to 6 lb, GRIPMASTER 1 lb to 9 lb, GRIPMASTER-Rehab 0.75 lb to 9 lb, PRO 5 lb to 13 lb. By isolating each finger, the stronger fingers cannot compensate for the weaker ones.