3-in-1 Multi-function Stud Center Finder Metal DetectorAn easy to read LCD screen and ergonomic non slip handle make it easy to detect targets on the wall. Automatic calibration anywhere on the wall to find studs, metal rebar or live ac wires very quickly and easily, Move the instrument close to the wall and move it slowly. When metal, stud or AC cables are detected, it will show signal strength and beep. According to the signal strength, the exact location of the material can be judged to avoid drilling