ALLOSUN 4 in 1 Ultrasonic Distance meter/Wood Stud Finder/Metal Detector/AC Wires Tracker Power supplied by 1 piece 9V (6F22) battery. (Not provided by seller) Distance measure with imperial or metric system. Accurately locate hidden metal pipes, live wire, stud and wooden frames. Audio indicator and LCD display. 4 in 1 distance measurer, stud/metal/AC wires detectors.