A Transcutaneous Electrical Nerve Stimulation unit (TENS unit) is a device that delivers electric current to the skin via electrodes to stimulate the nerves. It was initially designed for the purposes of nerve stimulation and pain relief in the medical field, but TENS units are also used, and some are specifically marketed for, erotic electrosex stimuation.
TENS units use applied current to excite nerves and are usually connected to the skin with two or more electrodes. These electrodes may be the stick-on variety, or may be attached to a sex toy such as a dildo or butt plug. A TENS unit can produce tingling, pain, and at higher frequencies, they may cause involuntary muscular contraction.
Although TENS units were initially designed to treat back, neck, musculoskeletal pain, and nerve conditions, the technology was adopted for erotic stimulation in 1970s.
TENS units are generally considered to be safe, even for sexual use, but experts recommend that people with heart problems or pacemakers avoid using them. Electrostimulation should also be avoided by pregnant women.
Experienced BDSM practitioners also recommend that those who are new to e-stim try out a TENS unit on themselves before letting a partner use the controls.
Depending on the design, functionality, and extra features of the TENS Unit, it may also be called an electrosex powerbox.
