... up 999 indoor phones.2, Color or B/W video communication is optional.3, Intercom between door station ,indoor phone and guard ... unit is available.4, 90 seconds intercom and 20 surveillance is available.5, With card reader function ... unlock the door with IC card.6, Switch against uninstall is provided.7, Panel:Aluminium alloy8, Size:140mm*425mm color video ...