Zircon L50 StudSensor with WireWarning Detection indicates the presence of live AC voltage The Zircon StudSensor L50 stud finder locates the edges of wood and metal studs and joists behind walls, floors, and ceilings. Its easy-to-read display screen indicates stud edges, SpotLite Pointer shines a beam of light on the wall to clearly identify the target, and WireWarning Detection indicates the presence of live AC voltage. Its patented pivot pinch grip and contoured shape provide an easy, secure hold in either hand, at any angle. Features: StudScan mode locates the edges of wood or metal studs up to ¾ in. (19 mm) deep DeepScan mode doubles the scanning depth to 1 ½ in. (38 mm) READY icon displays when calibration has been completed successfully Easy-to-read LCD display indicates when a stud edge is approached Zircon\'s patented “over-the-stud” indication alerts user to start the scan in a new location if scanning begins over a stud WireWarning detection indicates the presence of live, unshielded electrical wiring up to 2 in. (51 mm) deep SpotLite Pointer shines an arrow-shaped light on the wall to clearly indicate the edge of the stud Patented pivot pinch grip for a comfortable, secure hold in either hand, at any angle “V” marker groove for more accurate marking of stud edge location Specification: Dimensions: 168 mm x 71 mm x 43 mm Weight: (126 g) without battery Battery Type: 9V alkaline, not included Position Accuracy: Up to a depth of 3⁄4 in. (19 mm): Typically within 1⁄8 in. (3 mm) using the dual scan and mark procedure Up to a depth of 1½ in. (38 mm): Typically within 3⁄16 in. (5 mm) using the dual scan and mark procedure Depth: StudScan mode: Up to ¾ in. (19 mm) DeepScan mode: Up to 1½ in. (38 mm) WireWarning Position Accuracy: Typically 90-250 V at 50-60Hz within 6 in. (152 mm) of a hot, unshielded wire in drywall WireWarning Depth: In typical wall with Romex wiring, wire can be detected up to 2 in. (51 mm) deep