Add another intercom to your Doorbell Fon Door Answering System (sold separately). The Doorbell Fon Door Answering System connects your doorbell to your telephone, so you'll be able to pick up any extension in the house to talk to your visitor. The Extra Aluminum Intercom Station is the ideal add-on box for an additional entryway to your home. When a visitor presses the non-mechanical sensor button on the included aluminum door box, the telephones will ring with a distinctive ring to let you know someone is at the door. Pick up any telephone to be connected with that door automatically. The flush-mount Extra Aluminum Intercom Station installs using a single pair of wire. It is vandal resistant and mounts conveniently into a 2-gang masonry box. The station is weather resistant and features an environmental-grade sensor button. By installing a modular add-on, you'll be able to add even more functionality to this doorbell answering system. The Inbound Relay Trigger Controller provides momentary contact closure from the push button on the door box. This can be used to trigger a door chime, lights, or even a camera for added security or alert signals. The trigger controller as well as any door chimes, lights or cameras are sold separately. An Outbound Relay Trigger Controller provides dry contact closure off the star key (*) on your telephone to operate an electrical device, such as a door release, to allow entry to your visitor without your having to leave your couch. This is especially handy when used on electric gates at the end of the driveway or property. The Extra Intercom Station is also available in ivory, brass and white.