The NM100 system is a full-function intercom and music distribution system designed for retrofit applications in residential use. The 'Master' unit can replace older intercom systems that use three-wire or four-wire connections to the room stations. The system supports up to 15 remote stations when retrofitting a 4-wire system, and 13 remote stations when retrofitting a 3-wire system. The built-in AM/FM radio tuner allows setting eight AM station presets and eight FM station presets. The backlit liquid crystal display shows the operation mode, audio source, radio frequency, volume setting, and time. With the optional NC300 6-disc CD changer installed, the display shows the disc number selected and the track number currently playing.