MultiScanner i520 One Step quickly and easily locates the edges and center of wood and metal studs and joists behind walls, floors and ceilings. It also locates metal as well as live AC electrical wiring. A 4-mode switch makes it easy to change functions, while the ultra-bright display screen, Spot Lite Pointing System and audio tone all indicate the location of the Karls Hardware. The signal strength indicator helps to distinguish between shallow and deep Karls Hardwares. Stud scan mode locates the edges and center of wood or metal studs up to 3/4 in. deepDeep Scan mode doubles the scanning depth to 1-1/2 inchAn ultra-bright LCD screen indicates direction, edges and center of studsAC Scan finds and traces live, unshielded electrical wiring up to 2 in. deepMetal mode detects ferrous metal, such as rebar, up to 3 in. deepWire Warning detection indicates the presence of live, unshielded electrical wire up to 2 in. deep in stud and metal scanning modesACT (Auto Correcting Technology) automatically corrects common user errors, such as when scanning begins over a stud