"Five Scanning Modes: The stud finder provides 5 scanning modes in total for detecting. Depending on the tasks you have, you can switch to any mode you want.Digital LCD Display and Audio Alarm: The wall stud locator features a large LCD display with a large audible warning to detect the precise location of objects, so you can know what is behind the wall before to do a job, avoiding problems and dangersAccurate and Fast Locating: The wall scanner adopts smart micro-sensor chip which can precisely and quickly find the edges and center of metal, nails, joists and pipes, live AC wires behind walls , floors and ceilings.Automatic Calibration: The wall finder can be automatically calibrated anywhere on the wall to successfully find the center of studs very efficiently. This feature greatly reduces errors in the application, and ensures that most objects behind the wall can be detected.Wide Use: The beam finder is the widely used portable devices for home improvement projects. This electronic stud finder quickly locates hidden wood, metal and AC wires in the walls, floors, towers and ceilings of the house.Features: 1. Wireless and portable. Five scan modes: (1) 1/2" Scan: 1/2" (13cm) scan mode locates the center and edges of the wood. (2) 2.5cm Dowel Scan: Medium scan locates center and edges of wood up to 25mm depth. (3) Dowel Scan: Deep scan locates center and edges of wood up to 38mm deep. (4) Metal Scan: Metal detects metals up to 60mm deep. (5) AC Scan: AC scanner detects under voltage up to 51mm deep. Backlit LCD display and sound indication. 4. Automatic calibration of all detected functions. Low battery indicator. Power supply: 1 x 6F22 9V battery (not included). Tips for use: Select probe type, then press and hold the side button and scan horizontally across the surface of the object. Keep the tool flat against the wall and do not rock, tilt or press hard as you slowly glide across the surface to scan. A pointed down arrow and an indication will light up, indicating the location of the edge of the nail. Keep dragging. When the center of a stud is located, the full bars on the signal strength meter, the pointed arrow on the top of the bars, the center indication will appear and the buzzer will sound. Contents: 1 stud finder"