Panasonic KX-T30865-W Door Intercom Requires Door Card in PBXDesigned for two way conversation with front gate or door Can be mounted on any flat surface, or over an electrical junction box Requires one pair of wires connected to the control unit, and has internal wire clamp terminals for two stripped wires Panasonic door phone Standard door phone Compatible with all Panasonic PBX telephone systems White Requires PBX Door Card for connection. Check your appropriate system for the right card needed.