1,video door phone ,color video door phone video ... and administration center, ccd or cmos monitor; remote unlockFeatures:1, One door station can support 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.5, With card reader function,you can unlock the door with IC card.6, Switch against uninstall ...