Come with LCD-screen and audio-alarm, convenient to use.    This will keep you away from AC-power line and no need worry about safety hazards during construction.    You can switch to the appropriate mode to help you find the center and edge of the , joist or beam, live AC-wires and metal in the wall accurately.    4 in 1 Multi-function Detection: The stud scan features 4 modes: Stud scan: 0.75in/19mm deep, stud scan: 1.5in/38mm, metal scan: 2.36in/60mm deep, AC-scan: 2in/51mm deep    Accurate Smart-Sensor: This stud finder is equipped with upgraded sensor chip. It can accurately and quickly locate the studs, metals, pipes and live AC-wires behind wall, floors and ceilings.           Specifications:     Material: Plastic    Scan Modes:    Stud Scan 1: 0.75in/19mm    Stud Scan 2: 1.5in/38mm    Metal Scan: 2.36in/60mm    AC-Scan: 2in/51mm    Display: LED Backlit Screen    Size: About. 172x76x37mm/6.77x2.99x1.46in           Package Includes:     1xWall Scanner