One Switch Operation Ultimate Sensitivity Does not require adjustments Rugged, high-impact ABS case with reinforced coil compartment Detects medium sized pistol from 9”; large knife from 6”; razor blade and box cutter from 3”; foil-wrapped drugs and tiny jewellery from 1” Large 10” scan surface for quick, thorough scanning No tools required to change 9V battery Sharp audible alarm and bright red LED light indicates detection of metal Momentary push button temporarily eliminates detection of nearby ambient metal such as rebar, metal walls, etc.