1.[5 in 1]The digital wall scanner has 5 scanning modes, includes 1/2", 1" and 1-1/2" scanning mode to locate the center and edge of woods, beam, joist, metals or deeply embedded objects. Metal scanning mode to detect ferrous and non-ferrous metal up to a depth of 2.36"; AC scan detects unshielded AC voltage lines up to 2". 2.[Accurate & Rapid]The stud finder adopts intelligent micro-sensor chip with highest sensitivity, which can accurately and quickly find edges and center of metal, studs, joists, pipes, live AC wire behind walls, floors and ceilings. 3.[LCD Display & Audio Alarm]This stud finder comes with LCD display and sound alarm, which can detect the exact location of the objects. When find the objects, the intensity of beeping tells whether you are more close to the target. 4.[]Turn on the stud finder, lay it flat on the wall, press the scan button and it is ready for calibration. When the wood, metal and AC wires hidden is found, the intelligent micro-sensor chip will flash and beep.