850 Series systems are available in multiples of eight zones.

An 850 series door annunciator comprises the processor and an uninterruptible power supply with  backup battery in a metal enclosure, and the 870-LT series remote control and display panel. The  Processor comes factory ready to monitor normally open or closed alarm sensors. Installation is just a matter of connecting the sensors to be monitored to the processor and the remote display panel.  A class 2 power transformer is supplied which must be inserted into a 120V unswitchable electrical outlet.  Optional equipment includes the  870-1LT remote control and display, and the optional output relay banks 880-8RM or the 850-8SS.