Interfaces To Legacy And IP Phone SystemsExpandable Up To 360 ClassroomsCat 3/5 Telcom/Data Wire InstallationIntegral One-way And Handsfree AmplifiersEmergency Voice Announce Over SpeakersIntegrated Wav File SupportOff-site Programming And DiagnosticsSerial Port Used To Display System Activity6 Internal Software Programmable Tones8 Software Controlled Output Relays6 Software Controlled Switch InputsU.L. 813 Listed, Fcc Part 15 Class BCalendar Based SchedulesIntegrated Wav File SupportEnhanced Caller IdHandsfree Talkback3 Auxiliary Audio InputsAll Call PagingAdvanced Emergency FunctionsWall Or Rack MountUnlimited Time SchedulesMicrophone InputEmergency All Call PagingEasy Windows« ProgrammingArchitectural Room NumberingClock Synchronization This product ships in approximately 1 days