ABB Busch-Jaeger-Welcome® intercom set

The following components are generally required for normal video/audio communication in letterboxes:

• Microphone and loudspeaker: For audio communication, a microphone and a loudspeaker are required, which can also be integrated into the letterbox.
• Control unit/system center: A device that controls the communication between the outdoor microphone and the indoor stations.
• Indoor station: A display with loudspeaker inside the house to be able to see and speak to the person at the door.
• Connection technology: Depending on the system, this can be 2-wire bus technology, LAN or WLAN.