OneStep® tool finds the center and edges of wood and metal studs and joists up to 1-1/2” deep in walls, floors, and ceilings. Perfect for both professional builders and home improvement enthusiasts. WireWarning® Alert indicates the presence of unshielded hot electrical wiring. An easy-to-read LCD screen indicates direction, center, and edges of studs. A signal strength indicator helps determine the target’s depth. CenterVision® technology locates the center of wood and metal studs with just one pass. SpotLite® Pointing System and audio alert identify stud centers instantly. ACT™ Auto Correcting Technology checks calibration 10 times per second and recalibrates automatically to ensure accuracy. Uses 1 9-volt battery (included).