I picked up a CVS branded tens unit for $30 that only had one setting and relied on button cells. Replacment pads were very expensive. I got this for $20 and picked up a bunch of electrodes to go with it, and ended up immediately returning my CVS tens unit. This thing is amazing. Power is adjustable from imperceptible levels to convulsion inducing shocks, and there are lots of modes to play with. I originally got this to treat my sciatica, which it did well, but It's also great to relax your muscles after a workout. I brought it on a ski trip to use on my feet and legs as I use very stiff race boots, and it greatly improved my comfort throughout the week. Battery life is pretty good, and the wires are compatible with every aftermarket electrode I tried. Adhesion is so-so but that's the case with all body electrodes. It works best on clean, shaven skin with fresh pads.