It comes in 3 different levels of difficulty: Green-30lb max resistance (easier)-for lighter weight people and warming up, Black-40lb max resistance (medium) for average weight men to train with and Red 50lb max resistance (difficult) for big guys or lower rep strength training. Use It- GripPro trainer is very portable and easy to use, almost anywhere/anytime.at your desk, stuck in traffic, walking, on the treadmill, etc. Try 3 sets of 30-100 reps a couple times a week for best results over time. Its also great for stress relief. Why It's Best- When compared to other portable hand/forearm exercisers GripPro trainer has a great feeling in the hand and is superior to: Grip type balls-extremely boring and mostly therapeutic; metal spring devices with handles-awkward, uncomfortable and due to the fulcrum of the spring give an uneven exercise; hand held gyros-difficult to use. Who Needs It- Few people appreciate how importance of grip strength.

Green - 30lb light resistance for lighter weight people and warming up.

Black - 40lb medium resistance for average weight men to train with.

Red - 50lb heavy resistance for big guys or lower rep strength training.