Compact intercom for surface-mounting with extension, white

This device consists of a compact surface-mounting telephone 10-511 and an expansion module. The expansion module has 10 free function keys with feedback LEDs and a name plate. You can assign one of the following functions to the free function keys: communication with an external unit and switching of the door opener relay, internal call, contact-status indication of the bus indicator module (10-840), (de)activation of call diversion or transmission of a control function.