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.Device will work with connected appliances. Works with all old 2G sim cards and most 3G sim recommended standard Pay As You Go sim from EE, Vodafone. Won't work with O2, but you can take advantage of unlimited free calls with Lebara. Very simple to operate: insert sim card into the bug and install the device in the room where the bugging is to be implemented. The unit will turn on both built-in microphones, without making any noise or flashing lights. 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. Size: 143mm x 86mm x 30mm Please note that the depth of the back box needs to be at least 35mm. 1x Double wall socket with GSM bug 1x User Manual. 2x Double wall socket with GSM bug 2x User Manual. 3x Double wall socket with GSM bug 3x User Manual. The images are for reference only. Please take the item you get as the standard. Please repack the item carefully. We do not work on holidays in Hong Kong. Your action will help us offer our milk and bread. Certain images/photos incorporated into this template are the property of JuperiterImages, used with permission under license. The item "Wireless Audio GSM Bug Spy SIM Listening Device Main Plug Socket Surveillance BE" is in sale since Wednesday, February 27, 2019. This item is in the category "Home, Furniture & DIY\Smart Home & Surveillance\Home Surveillance\Home Surveillance Parts & Accessories\Other Surveillance Parts & Accessories". The seller is "bestpartner365" and is located in Hong Kong. This item can be shipped worldwide.