Refurbished Avaya IP400 16 V2 expansion module.
Part Number: 700359904
Will provide an additional 16 plain ordinary telephone (POTS) ports for use with analog telephones.
IP403, IP406 V1, IP406 V2, and IP412 control units
IP500 control unit running R4.2 or earlier - professional edition is required
IP500 running R5.0 or higher up to and including R9.0
IP500 V2 running R6.0 or higher up to R9.0