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. 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. 7 in 1 Multifunctional Stud Finder: You can get a wall stud finder and one user manual. 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. Note: The buttons are black, the actual product may have slight color difference or difference Colour: Black Material: ABS Operating Temperature: 0-40C Battery: 1 x 9V, 6F22, 900mAh(Without battery) Operating Current: Less than 20mA Battery: Low battery indicator Positioning: Wooden terrier & edge positioning Package Contents: 1 x Wall Stud Scanner 1 x English manual Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.