The StudSensor HD70 OneStep stud finder features a bright, backlit LCD display and Target Spotlight that illuminates on-screen when you've found the center of a stud. StudScan mode locates the center, edges, and direction of wood or metal studs up to 3/4" (19 mm) deep. DeepScan mode doubles the scanning depth to 1 1/2" (38 mm). WireWarning detection indicates the presence of live, unshielded AC electrical wiring up to 2" (50 mm) deep. Auto Correcting Technology automatically corrects common errors, such as when scanning begins over a stud. Signal Strength indicator helps to distinguish between shallow and deep targets. SpotLite Pointer shines an arrow-shaped light on the wall to clearly indicate the center of the stud. Translucent base and illuminated  V marker groove for more accurate marking of stud location.