So if you have ever been to the chiropractor, you may have been hooked up to the big electrical stimulant machine. We call it a stim in my house. But they make you feel pretty strange since it forces your muscles to contract, but it is relaxing after a while.
This is the same thing, just a bit less powerful and more tuned to home use. You can throw it on after a long day and use the 4 pads to get your shoulders and back or whatever it is that ails you. All in all, a pretty nice deal.