With its stainless-steel door entry system, Auerswald presents a stylish new design. Visitors are safely guided by the system’s extralarge buttons with integrated power-saving LED lighting. Adapting an existing Auerswald installation for the TFS-Dialog 300 requires very little effort – and ensures you have the latest technology. You simply screw the door entry system to the flush-mounting box. If yours is a new installation, the appropriate flush-mounting box is included with the system.Auerswald's a/b switch modules are made especially for TFS-Dialog 300. They can be connected any- where on the a/b line between the door entry and PBX systems, allowing you to use an existing doorbell or to switch on the stairway light.Up to six a/b switch modules per TFS-Dialog 300 can be used with only one 2-wire cable. Each button can be assigned to and control one or several switch modules. Without problems, the modules fit in any of the existing flush-mounting junction boxes.