From company website: "The StudSensor HD70 center-finding stud finder adds CenterVision technology to simplify and enhance stud detection. The HD70 locates both the center and edges of wood and metal studs in a single pass, making it easier and faster to finish your project while still ensuring precision. Like the HD55, this tool is equipped with two scan modes to scan through one layer of drywall up to 3/4 inch deep or through two layers with DeepScan mode. Ideal for locating studs through drywall or joists in wood flooring and subflooring, the HD70 features WireWarning Detection to alert you to live, unshielded AC wiring, promoting safety as you scan."