This Fully Functioning Double Mains Adaptor is fitted with our very latest GSM listening technology - and is another first from JJN Spy Technology! Simply plug it into any mains socket and monitor the room conversations from anywhere in the world. Just call the supplied number and the unit will silently switch on enabling you to listen to sound up to 30 feet from wherever the device is fitted. Sound is filtered and 100% buzz free for perfect audio clarity. With mains power you no longer need to recover and recharge the unit making perfect for long term monitoring and this model also features a battery backup system so that the unit can still be monitored for up to 12 hours in the event of a power failure. The GSM Adaptor will work when connected to any 3-Pin UK type socket with 220-250V supply and where a 900/1800 MHz mobile phone network is available.