Features:

• 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 fingers anytime, anywhere
• Extra-heavy tension strength of 11 pounds per finger for extremely strong hands

I have a couple of these and needed one that has more resistance. This certainly fit the bill and I would highly recommend it. I moved up from the 9lb standard model.

My fingers are stiff due to osteoarthritis. And this is a wonderful tool to help me adquire more strength.

I was in need of a more powerful hand strengthening tool and this one is it!!
I play a lot of tennis and I coach other sports that require a good grip. This device is a great help.
I plan on getting another one with less tension. I like how it accentuates each finger for building strength.

I have very large hands and I found this to be nearly unusable because my fingers are too large to use the individual buttons without getting snagged on the neighboring buttons. The Black Diamond Forearm Trainer works a lot better for me, although it is a little too easy to squeeze. I'm going to try the Grip Pro Trainer Red-50Lbs- next.

I bought this to continue strengthening my hands for guitar. I originally started on a 7 lb per finger Gripmaster, which after months of use, I found was far too weak for my hands.

It will, of course, be extremely difficult to use if it is your first hand-strengthening product, and the Gripmaster Pro design is slightly larger than the standard Gripmaster, so people with small hands, be warned.

All in all, a great product.