This device is an audio surveillance spying device which uses a SIM card allowing you to call and snoop on those in the room. It has a magnetic core allowing it to be attached to metal objects which ideally should be hidden. The microphone is built in to the device and is activated when you call a phone number. It can pick up audio from around 10 meters away. The system works silently so that it doesn't get found. The battery will power the device for 2 to 3 hours and if an external battery is used it can get about 6 to 7 hours of usage. The GSM parts of the device work on 900, 1800 or 1900MHz (tri-band).
The ZRAD costs $149 and is available from Vavolo.