Non Contact Voltage Detectors, Battery, 1000 V no checkout Fiberglass handle for increased handle Fiberglass handle for increased handle strength Double face forged steel hammer head for maximum durability Overstrike protection to prevent handle breakage Epoxy connection for trusted head retention Used for heavy hammering Eliminates knot movement resulting in the most effective cleaning action circuit breakers and cables or to find a break in a wire Patented automatic self test verifies the integrity of the unit Bright LEDs flash and audible alarm sounds if voltage is present Silent mode feature for use in quiet settings Automatically turns off after five minutes of non use to conserve battery life