Depth Detection (Depth detected from wall surface: Up to 3/4 inch for wood studs, metal studs, 2 inches for live wire): Wood 3/4 in (19 mm); Metal 3/4 in (19 mm); Live wire 2 in (50.8 mm). Detects wood/metal studs. Center find stud finder. Detects live wire. 2 AAA. Center marking channel for convenience. Slim profile for easy use and storage. Audible alert for clear notification of stud location. Directional LED arrows for visual guidance to stud location. Constant auto-calibration allows for the ability to begin on a stud. US & Canada only. Guaranteed Tough: 3 year limited warranty; 1 year free service; 90 day money back guarantee. Details on the Limited Warranty can be found on DeWalt.com. DeWalt.com. Made in China.