Description Hidden in a fully functional double wall socket, it will work with connected appliances. Modern covert device for real time audio monitoring with voice activated call back function. This device is manufactured and assembled by us in the UK. Can be used in normal mode or "call back" mode (call you when it detects a noise or voice in the area). Call back mode can be activated or deactivated by text message, so physical presence by device is not required. Has unlimited range - unlike FM transmitters, walls or terrain do not affect the quality of reception. You may be halfway around the world and still hear what's going on in your house, garage or at work. Brand new, high quality. For security reasons sim card will not be included (only person using the device should know the mobile number). It won't work with Three, O2, Lycamobile, Giff Gaff and Tesco networks. It works just like mobile phone, but without screen and keyboard. Very simple to operate: insert sim card into the bug and install the device in the room where the bugging is to be implemented. To start listening you should phone the sim card located in the device. The unit will turn on built-in microphone, without making any noise or flashing lights. Features: 1. No signs on the exterior that would give away the devices purpose 2. No flashing lights or sounds when activated by your call 3. Works with the frequency of 850, 900, 1800 and 1900Mhz 4. Continuous power when connected to mains supply for long term audio monitoring 5. Weight: 180g 6. Size: 143mm x 86mm x 30mm Please note that the depth of the back box needs to be at least 35mm Package contains: 1 x Double wall socket with GSM bug 1 x User Manual