LED Light AC Electric Voltage Tester Volt Alert Pen Detector Sensor Electric Socket Wall AC Power Outlet Voltage Detector Sensor Tester Pen 90-1000V.ch20151030008 A perfect tool kit for home and electric industry uses Ideal design for testing power cables, circuit breakers, wall sockets, junction boxes, fuses, etc Just press the button, white LED light can be always on when there is absence of voltage Powered By: 2 x AAA Batteries (Not included)