Accurate calibration lets the line detector quickly identify metal, wood or live AC behind walls, floors, and ceilings. Do not move or shake the device until calibration to zero is complete, otherwise the calibration will fail (calibration cannot be done in air). Note: Automatic calibration must be performed in an area free of nails, AC cables or metal to ensure accurate results. Five detection modes for versatile use: - 1/2 in (13 mm), 1 in (25 mm), and 1.5 in (38 mm) wood/beam detection - Metal Scan (60 mm) for locating metal - AC Scan (51 mm) for live wiring These modes help you locate centers and edges of wood, beams and metal, and detect iron and non-ferrous metals. AC voltage sensing covers 80 to 240 VAC. Widely usable: lightweight and durable for DIY projects. Use for installing TVs, bathroom cabinets, picture frames, garage shelves, and more. Helps reduce risk by identifying hidden hazards before drilling or cutting. Suitable for use at home, in the office or in a workshop. Use scenarios: - Mounting a TV or frame: locate studs and avoid live wires - Installing bathroom cabinets or shelves: find studs and pipes behind walls - Wiring and cable management: scan for live wires and metal conduits before drilling in a workspace or office