Zircon MultiScanner 440 Edge Finding Stud Finder with Metal and Live AC Wire Detection and LCD Screen Zircon's MS 440 is a multi-surface scanner with 4 modes that detect studs, metal and live AC wiring to help you easily find studs and avoid hazards while mounting a TV, hanging cabinets, installing garage shelving and more! Both StudScan and DeepScan modes locate the edges of wood or metal studs while the Metal Scan mode finds both non-ferrous metal (such as copper pipe) and ferrous metal (such as rebar) WireWarning Detection indicates the presence of live, unshielded electrical AC wiring while scanning in StudScan, DeepScan, and Metal Scan modes AC Scan finds and traces live, unshielded electrical AC wires One fully charged 9V battery, not included, is required for the multi-surface scanner to run at optimal performance