Electronic hands-free massager (Tens Unit) used to relieve back, leg, neck, and shoulder stiffness or fatigue and It runs on a 3 AAA battery and it's powerful. but also comes with an attachment for your computer’s USB port for powering the device.
It's smaller than Massage Mouse. Also available, for a nominal price, an a/c adapter so you can plug your device into an outlet to receive power.
Transcutaneous electrical nerve stimulation (TENS) is the use of electric current produced by a device to stimulate the nerves for therapeutic purposes. TENS by definition covers the complete range of transcutaneously applied currents used for nerve excitation although the term is often used with a more restrictive intent, namely to describe the kind of pulses produced by portable stimulators used to treat pain. The unit is usually connected to the skin using two or more electrodes. A typical battery-operated TENS unit is able to modulate pulse width, frequency and intensity. Generally TENS is applied at high frequency with an intensity below motor contraction (sensory intensity) or low frequency with an intensity that produces motor contraction.
TENS is a non-invasive, low-risk nerve stimulation that reduces pain, both acute and chronic.