NEC Univerge SV8100 670100 PZ-BS10 3-Port Expansion Board for Controlling Chassis (Refurbished)Key Features: Mfr. Part #: 670100 When adding additional chassis to the system to expand the capacity, a PZ BS10 must be installed in the Controlling Chassis and a PZ BS11 must be installed in all Expansion Chassis This connection is required with any multiple chassis setup The PZ BS10 connects the Controlling Chassis to the Expansion Chassis by connecting to a PZ BS11, which is installed on each Expansion Chassis These Expansion Interface Units allow