-- Detection. With automatic calibration for easy and precise detection, there are three modes to select : wood studs, metal objects (rebar, studs and steel/copper pipes) and live wiring. --Accurate Detector Technology. This stud finder can locate center of wood studs up to 3/4-Inch (18 mm) deep, metal studs up to 11/5-Inches (30 mm) deep, Wire Warning detection indicates the presence of live wire up to 2". --High Efficiency. The easy-to-read LCD screen accurately displays what type of stud you are looking for as well as its position and the battery status of the device. --Easy to use. Only two buttons ,first select the probe type ,then just press and hold the side button and scan horizontally across the object surface. Auto power off without any operation after . --MEET ALL YOU NEED It is light weight and has ergonomically designed one-key-operate handle. Specification: Battery power : 6F22 9V battery (Not Included) Shell Material: ABS Stud detecting depth: 18mm behind wall Metal detecting depth: 30mm AC Wire: 90 ~ 250V 50mm Size: 155x72x28mm/6.1x2.83x1.1inch Weight: about 127g(NO Battery) Package Includes: 1 X Stud Finder Note: The color may be different for different display, pls understand Pls allow 1-3mm error due to hand test, thank you!