all-sun TS73 3 in 1 LED Wood Stud Finder Metal scanning for finding nail, pipe, rebar, and other hidden metallic object When detects an edge of object, the top signal LED lights as an indicator When detects an object, the spotlight appears and mark in the groove position Owns there different functions: stud finder, metal Detector and AC Tracer Power supplied by 1 pieces 9V(6F22) battery.(Not Provided by Seller)