Stay safe and work smart, as this rubber gripped unit detects wood, metal studs, rebar and live wires hidden behind walls using the deep stud sensor (up to 1-1/2 In. deep for wood and metal studs; 2 In. deep for rebar). Electronically locates wood & metal studs up to 3/4 In. (19mm) depth through walls, floors & ceilings in regular mode. Its large, LCD screen makes for easy reading, while an automatic power-off feature shuts it down if left idle for more than two minutes. Low battery indicator, and it uses a 9V battery. The battery is included.