A domestic intercom system is useful for keeping in touch with family members around the house, and this set of 2 couldnt be simpler to use. Plug in, and the wireless signal uses Power Line Carrier (PLC) technology to stream sound down the electrical power line. It can be used for monitoring another room, or simply for announcing when dinners ready! Supplied as a set of 2 intercoms, however the system supports up to 4 intercoms or channels, allowing you to expand your communication network as needed to cover more rooms in your home. Once the Call button has been pressed, its hands-free operation. High contrast, large buttons are simple to use.