This pen-type voltage detector is easy to use. Simply place the white tip where you wish to detect voltage. If the unit detects any voltage it will indicate it by a red LED light and an audible alarm. It can be used to detect voltage in household appliances or electronic equipment.The unit features a built in LED torch light for vision when testing in dark areas. Equipped with a pocket clip and supplied with an impact resistant ABS case it is compact and easily portable around the work environment.