The Stud Sensor e 40 quickly & easily locates the edges of wood & metal studs & joists behind walls floors & ceilings. It features a new user-friendly interface an enhanced Spot Liteandreg; Pointer shines a beam of light on the wall to identify the target & Wire Warningandreg; detection indicates the presence of live AC voltage. Its new patent-pending pinch grip & contoured shape provide an easy secure hold in either hand at any angle. Locates the edges of wood or metal studs up to 3/4 inch (19 mm.) deep. Deep Scanandreg; mode doubles the scanning depth to 1 1/2 inches (38 mm.). New Ready light indicates when calibration has completed successfully. Red arrows light up sequentially as the stud finder nears a target. New Edge light indicates when the tool is over a stud edge. Updated Spot Liteandreg; Pointer shines an arrow-shaped light on the wall to mark the target.