7 in 1 Multifunctional Stud Finder: You can get a wall stud finder and one user manual. Calibration Before Use: Place the detector to be detected. Press the MODE key to switch on, press the measurement key, when the LCD aperture gradually become smaller hear the 'di' sound that indicates that the calibration is complete, can be used. LCD Display & Sound Indication: This multifunctional wall scanner detector has a graphic LCD display which can indicate the scanning modes, calibration function and remaining battery indicator. The stud finder also features a backlight for use in the dark area. This stud finder wall detector provides a beep alert, which could remind you of the position of the stud. If there is a stud, metal or AC wire, you can know the position quickly and clearly. It is a hand-held, d wall test instrument designed to detect magnetic metals such as rebar and iron pipe; non-magnetic metals such as aluminium and copper pipe; and non-metallic metals such as wooden and electrically objects such as electrical wires, hidden in walls, ceilings and floors., Manufacturer: Akfldms