... audio bug at hidden place,then dial the card number to monitor your target,you will hear ... 24 hours non-stop power supply. All GSM SIM card compatible. Specification: Frequency:900, 1800, 1900 Power Supply ... :24 hours Non-stop Card Compatible:GSM / SIM Microphone Range (Meter):5~7( ... to monitor the surroundings, just dial the sim card no., you can monitor the voice around 5- ...