Card to be inserted inside switchboard Art. 2906, (max 1 card per switchboard) -allows the door entry phone service to be added, integrated with the telephoneservice. Switchboard Art. 2906 is enriched with the following functions:Audio communication with door entry phone external unit, four separate callinputs from door entry phone external unit, relay controls to activate: dooropener, gate opener, supplementary actuator devices. Remote activation of2 relays, follow me over telephone network of door entry phone calls.