4-in-1 Scanner Plus Depth Detection - The wall scanner includes four different scanning modes for wood, beams, joists, metal, AC wires, and deeply embedded objects behind floors, ceilings, walls. STUD mode detects wood beams and joists up to 0.75 inches deep in drywall. DEEP mode detects wood and metal parts up to 1.5 inches deep. METAL mode detects pipes, rebar, aluminum, and copper up to 2.36 inches deep. AC voltage and live wires up to 2.0 inches deep._x000D_Upgraded LED Display and Clear Sound Warning - The wall stud sensor features a large LED screen display and a loud and clear sound warning. As you move this tool along the wall, the LED screen indicator gives you clear directions and the exact location of the object, and its sound warning shows you if the object is at the edge or center of the wall._x000D_Automatic Calibration for Efficient Scanning - When you turn on the stud detector, it automatically calibrates. Make sure it is calibrated in a location where there are no studs or AC wires nearby. In STUD AND DEEP mode, just calibrate on the wall. In METAL and AC mode, calibrate in the air.