... to wooden/concrete wall, 3-in-1 Stud/Voltage / Metal Detector with Easy-to-Read ... Screen Accurately locates hidden metal pipes, live wires, stud and wooden frames Easy to read LCD screen ... Detects wood up to20mm Auto calibration metal, voltage, stud detection Audio and visual indication Operated by one ... of 9V battery (battery not included) Stud detector, Voltage detector, Metal detector, 3 in 1 ...