High-quality hand exerciser with spring-loaded finger piston technologyIsolates and strengthens each finger individually for better overall coordinationImproves user control of bats, racquets, clubs, guitars, and other sports equipmentFits conveniently in your pocket; lets you strengthen fingers anytime, anywhereHeavy tension strength of 9 pounds per finger for strong hands 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. 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. Best of all, you can work out anytime and anywhere with the Gripmaster Pro, which fits neatly in your pocket when not in use. Tension (lbs per finger): Light (Blue) - 5 lbs Medium (Red) - 7 lbs Heavy (Black) - 9 lbs Extra Heavy (Gray) - 11 lbs