Comdial 7202-00 DX-80 Expansion Unit (Refurbished)Comdial DX 80 Expansion cabinet (4x8) used to expand the system capacity beyond the KSU1 limits. Includes 4 telephone CO lines, 8 digital telephone station ports and 1 analog power failure transfer port. More Information: Mnfr Part #: 7202 00 8 digital extension ports 4 Caller ID ready CO line ports 1 power failure transfer analog port