The Gripmaster Pro isolates and strengthens each finger individually, helping you improve your overall strength, endurance, and dexterity. A few daily workouts with the Gripmaster Pro and you'll enjoy better control of a baseball/softball bat, tennis racquet, or golf club, with each finger working in seamless unity with the others. High-quality hand exerciser with spring-loaded finger piston technology. Isolates and strengthens each finger individually for better overall coordination. Improves user control of bats, racquets, clubs, guitars, and other sports equipment. Fits conveniently in your pocket; lets you strengthen your fingers anytime, anywhere. You'll also find a ton of other uses for the Gripmaster Pro, including playing guitar or violin, rock climbing, bowling, target shooting, martial arts, yoga, or even relieving stress while clicking a mouse or gaming for hours on end. To keep things interesting and to accommodate certain uses, the company recommends several different exercises, including the "fingertip pinch," "flatfist," "powergrip," "wristflex," and "thumbpinch," most of which are explained on the Gripmaster website. Tension (lbs per finger): Light (Blue) - 5 lbs. Medium (Red) - 7 lbs. Heavy (Black) - 9 lbs. Extra Heavy (Gray) - 11 lbs. Extra Extra Heavy (Orange) - 13 lbs.