COMMAX Intercom Audio Phone Only DP-SS Used for COMMAX Multi-Unit SystemApartment/ In-House Intercom Unit (ROOMSTATION) for use with the Door Station (DR-nKM, DR-nKS, DR-nAM, DR-nAS, DR-nUM). Power Source: DC12V/500mA; Mounting type: Surface mounted type; Wiring: 4 wires (to door unit) and 2 wires for door lock; Dimension with handset: 70x210x80mm;..