W80DM VoIP SIP DECT multi-cell manager (requires at least two x W80B), connect up to 30 additional W80B base stations, PoE required, AC optional, SKU #PS5V1200US, supports up to 100 concurrent calls, up to 100 WP53H / W56H / CP930W / T41S + DD10K / T42S + DD10K. Note: In order to plan and implement a W80 SIP DECT multi-cell system, please purchase SKU #W80BDEPLOYKIT, which can be used for an initial deployment and all subsequent deployments. In order to pair and work with the W80DM base station in a multi-cell environment, the W80B requires firmware version 103.83.0.70.rom or newer, the W53H requires firmware version 88.83.0.90.rom or newer, the W56H requires 61.83.0.90.rom or newer, the CP930W requires firmware version 87.83.0.60.rom or newer, the T41S + DD10K or T42S + DD10K require firmware version 66.84.0.125.rom or newer.