Zircon MS 540 Multiscanner Center-Finding Stud Finder with Metal Detection and Live AC Wire Tracing Stud Scan Mode locates the center, edges, and direction of wood or metal studs up to 3/4" deep Metal Scan mode locates non-ferrous metal, such as copper pipe, up to 1.5 inches deep, and ferrous metal, such as rebar, up to 3 inches deep AC Scan finds and traces live, unshielded electrical wire up to 2 inches deep Ultra-bright display screen, SpotLite Pointing System and audio tone all indicate the location of the target 4-mode switch makes it easy to change functions