M&S SYSTEMS DMC4PACK 4-Wire Music/Communication Retrofit System Package *4-Wire Music/Communication Retrofit System Package * Designed as a retrofit for 4-wire intercom systems; Offers many of the basic components needed to assemble a 4-room, 1-patio & 1-entry door music/communication system;Kit includes: 1 DMC3-4 music/communication retrofit system master 4 DMC4RS room stations 1 DMC4RW patio station 1 DS3B door station with bell button 1 MC3 3-note chime module * WARRANTY: TWO YEARS