It works great! You can use 2, 4 or all 6 of the pads, and it has a bunch of different patterns for electro-massage. I use it all the time, and the pads are super sticky and you can use them over and over, and the battery seems to last forever before you have to recharge it.
They say that electro-massage will even block the pain signal going to the brain, so that's another plus. I had a cervical discectomy on my neck so I suffer from almost constant neck pain, and it feels great when I use it on that. When my back hurts, depends on how many pads I use. I usually use 4, but have used just 2, not so great for the back, and all 6, and that feels awesome.
Yeah that's a great little unit, easy to use, great price, I'd recommend it. They do caution about hooking it up going across you heart.