Based on the principles of TENS (Transcutaneous Electric Nerve Stimulation) itÂ’s designed to stimulate the nerves in any area of your body, triggering the release of endorphins from your brain to help ease aches & pains. Unlike other TENS devices there are no wires or sticky pads, so itÂ’s really easy to use, & the angled head means you can even use it on your back. ItÂ’s also battery operated so you can use it at any time, anywhere.