Non-contact AC voltage detector and LED flashlight combined * The voltage detector glows blue when it"s near AC voltage, and glows red when it"s at the source. * Detects voltages from 40 V AC to 300 V AC * Voltage detector glows blue 50 Hz - 60 Hz or 2.5 - 38 cm (1 - 5") away from source * AAA battery included.