Expansion switch is designed to accommodate 1 to 8 devices including call stations, other expansion switches, or remote control panels. Up to 35 expansion switches can be used in the 4800 system to support a total of 255 call stations. Expansion switch is to be used with the Cornell digital area of refuge system to allow additional call stations to be added to a system. Expansion switches can be located in a controlled maintenance room or closet. The enclosure includes (3) knockouts that are located at the top of the enclosure, and keyhole slots for surface mounting. The contractor shall furnish and install the Cornelles-4808 expansion switch as indicated on the plans. Expansion switch shall be mounted in Cornell provided enclosures.