Audio door speaker module with 4 call buttons for creating pure audio systems in 2-wire technology. With adjustment of the volume of the loudspeaker and microphone. For managing up to 100 call buttons when using the 2-row call button modules Art. 352100. Up to 50 call buttons are possible with 1-row call button modules Art. 352000. The door opener (max. 30 Ohm internal resistance) is connected directly to the S+ and S- terminals (18 V 4 A surge current - 250 mA holding current). An external door opener button (e.g. postal lock) can be integrated via the PL terminals. To be completed with the corresponding front panel. The device can only be configured physically (with configurators). Note: - This loudspeaker module is not suitable for video systems and cannot be used with a graphic display, keypad or induction loop. - The access systems (code lock, transponder) can only be used stand-alone. - When using the left row of call buttons on the loudspeaker module or the 2-row call button modules, the jumper (J1) must be pulled.