Sfera Basic speaker module for 2 wire audio systems. Fitted with loudspeaker and microphone volume adjustment. It manages up to 100 pushbutton calls using additional double row pushbuttons. It can be used for opening an electrical door lock directly connected to the S+ and S- clamps (18 V 4 A impulsive - 250 mA holding current 30 Ohm max) and the connection to a local door lock release pushbutton on the PL clamps. To be completed with surround plate. The device must be physically configured.