Great product
There's no end to the number of activities that involve hand, wrist and arm movements. Golf, typing, boxing, baseball, basket ball, arm wrestling. I box and practice MMA, and I love this thing. It's basically a gyroscope inside a tiny ball, you start it, via the string it comes with, or with your hand (a bit difficult)
After reciving this product I went through many stages with it, I couldn't use it, then I loved it, then I disliked it, and now I love it again. This is because it takes a bit to get used to the movements involved in accelerating the gyroscope, but once you get the hang of it you can really get a good work out for your hand muscles, and your wrist, and also your arm. A full speed dynaflex has to be held to be believed.
However addicting, the string used to start the dynaflex will probably break before you manage to learn how to start it manually. The product comes with a mini CD that has a nice video explaining how to start and use it, and mentions that a manual starter can be purchased (but not available on amazon) But with a little snipping, any shoe lace can be used to start this neat little machine
It's like the nintendo Wii, I broke this machine's string because I was SO addicted to using it
