The RF Wireless Signal Detector from KJB Security Products is a counter-surveillance device which locates hidden bugs using digital frequencies like Bluetooth and Wi-Fi as well as analog frequencies reaching up to 6 GHz in range. The unit can detect a variety of conventional bugging devices including FM-modulated transmitters, digital transmitters, GSM bugs, etc. Using sound to detect transmitters, the unit can produce a loop-back effect as well as utilize a microphone to find and transmit the beep. When a signal is detected the demodulation display will flash, and the detector will sound, depending on the type of transmission detected. The extra antenna allows the device to avoid interference from external sources in cities or near broadcasting towers.