Whupps sorry about that, I am guilty of not expanding acronyms quite often...
It's a "Transcutaneous Electrical Nerve Stimulation" device.
Mine, and I believe most are similar, is a little walkman-sized device that takes a nine volt battery, and connects to leads that then connect to electrodes (sticky pads) that you place on either side of the pain source... just by stickin' em on your skin.
If you think you may benefit I think most docs will give you a loaner for 30 days so you can try it out, then if you don't want to buy or bill it to insurance you can send it back to the medical company or doctor. Mine came with the UPS pre-paid and everything, but I'm keeping this bad boy, it has definetely helped enough to justify keeping it. If I'm in a flare, which i JUST was, it took enough edge off to actually get up. A major advance in my case!
It reportedly works by interfering with the pain signals transmitted from the source to the brain. I think there is more to it but that's what the layman info in the manual here says.
PM me or follow-up if you need any more info, I'd be glad to help if you want!