Video security intercoms can be very useful in home or business to verify who is at your door and if you want to let them in.If you know who is there you can push the unlock button on the unit and it will apply power to the electric lock to allow the door to be opened.The name brand we use is comlit.The monitors can vary in size according to what your budget is.The humble intercom system has changed a great deal in recent years and is no longer bound to only audio. Don’t settle for a simple audio intercom system when you can have the added convenience and security of video.Audio intercom systems are not as secure as video intercoms because the camera will allow you to communicate with guests without compromising your security.Video intercoms eliminate potential illegal activities such as break-ins, trespassers and vandals. Anyone who sees multiple cameras will think twice before committing any criminal activities.. Room Monitoring – With a central control panel and room stations set-up around the house you can use your intercom to monitor what is going on in those rooms. Keep tabs on the kids playing in the back room or use it to listen for when your sleeping baby awakes. With these units you can also communicate with the occupants of the room, so the kids will have no excuse for not hearing you ever again!