Garett scanners can detect medium-sized pistols at 9 inches; large pocketknives up to 6 inches; razor blades at 3 inches and a hat pin at 1 inch. Automatic retuning and battery check. 

Just press the ON switch, and the Super Scanner will alert you to even the smallest concealed metal weapons, using both an audio signal and a visual alarm. 

The unit features a Reduced Sensitivity mode for scanning near rebar floors, automatic tuning and battery check, and an end cover that allows battery changing without tools.