Key Features: -Ultimate sensitivity: detects medium sized pistol from 9" distance; large knife from 6"; razor blades and box cutters from 3" distance; foil-wrapped and tiny jewelry from 1". -Self-calibrating: digital microprocessor technology eliminates the need for periodic sensitivity adjustments. -Rugged, high-impact ABS case with reinforced coil compartment. Exceeds Mil-Std-810F (drop test) Method 516.5, procedures II and IV. -Large 8" scan surface for quick, thorough scanning. -No tools required to change standard 9V battery (included). -Optional rechargeable battery kit available. -Sharp audible alarm and bright red LED indicates the detection of metal. -Momentary push button helps temporarily eliminate detection of nearby ambient metal such as rebar, metal walls. -Three-color LED indication: Green LED indicates ON; Amber LED indicates LOW BATTERY: Red LED indicates ALARM. -Operating temperatures: -35° F (-37° C) to 158° F (70° C).