Fisher Security Hand-Held Concealed Weapons Detector Black. This hand-held metal detector from Fisher Security features a "momentary low" switch to eliminate interference from steel rebar built into many concrete floors. The Fisher Research Labs CW-20 Hand-Held Ferrous & Non-ferrous Metal Detector runs on one 9 volt battery and can be set to either quietly vibrate when finding metal or emit a high pitch sound. With a rugged and compact design the Fisher Research Labs CW-20 Hand-Held Concealed Weapons Detector pinpoints ferrous and non-ferrous metals with a smooth even motion sweep of the subject. Specifications for Fisher Research Labs CW-20 Hand-Held Metal Detector: Alerts: Audio - High pitch sound Silent - Vibration Dimensions: 16.50 x 3.5 x 1.4 in (42 x 9 x 3.5 cm) Weight: 14.1 oz / 399.7 gm Features of Fisher Research Labs CW-20 Hand-Held Concealed Weapons Detector: Detects Ferrous & Non-Ferrous Metals Operating Frequency 7.1 kHz (choice of 3 settings) Choice of Audio or Silent Vibrate Alarm LED Target Indicator Requires One 9 Volt Battery Momentary Low Toggle Switch Package Contents: Fisher Security CW-20 Hand-Held Concealed Weapons Detector Fisher Security CW20: CW-20 Hand-Held Concealed Weapons Detector Black