The TENS 210 is a battery-operated two-channel transcutaneous electrical nerve stimulator that creates electrical impulses. Intensity, duration, number per second and modulation of those impulses can be altered with easy to use controls or switches, all in a light-weight package. Prices do not include a fee for evaluation and training by a health care professional. The manufacturer highly recommends that you contact a health care professional and receive personal evaluation and training on the use of this product. Weight: 4 ounces (battery included) Dimensions: 3.7 in (H) x 2.6 in (W) x 0.9 in (T) Warranty: Device 1 year, lead wires 90 days