all-sun TS166A Wood Stud Finder AC Sensor Metal Detector Two selectable detection modes: all-metal mode and non-ferrous metal mode LCD display enables that you can read the function readings directly, simple and clear. Earphone equipped Power supplied by built-in Lithium battery The detecting range Depends on the size of metal, the metal purity, solid quality and the operation of machine Max detecting depth: 120cm for an iron plate which is 30cm wide, 30cm long and 1cm thick and which is buried in dry soil