Features: Stud Sensor Scanner Depth: Detects stud up to 0.71 inches (18mm) , metal up to 1.2 inches (30mm), presence of live wire up to 3 inches (50mm) . 3 in 1 : Multi-scanner stud finder for Wood, Metal, AC Current. Quickly locates edges and center of wood ,wall studs, metal pipes,wooden joist ,rebar behind walls, floors and ceilings, also indicates the presence of live AC wire . Easy to Read : LCD with digital display and continuous sound warning indicating you the location of the edges of the studs. Easy to Use : After battery installation,the unit is turned on with a long beep,when auto power off,press TEST button for two seconds to turn on again.Auto power off without any operation . Compact design is easy to hold and use. Low battery indication. Battery:AAA 1.5V*3not included. Specifications: Color: Blue,Red,Yellow,Green(optional) Material: ABS Battery Power: AAA 1.5V*3(not include) Stud Detecting Depth: wood 30*30mm:18mm Metal Detecting Depth: Iron Pipe 25mm:30mm AC Live WiresAC 90-520V live wire5cmfrequency at 50-60Hz Operating Temperature and humidity: -7-40,