Panasonic KX-TD816 Key Service Unit (Refurbished)This KSU is initially configured for 4 lines and 8 Stations but it is expandable to 8 lines and 16 Stations (32 Station max, with XDP). More Information Super Hybrid Station Ports can support Digital KX T7200 and Digital KX T7400 Series, Analog KX T7700 Series, and KX T7800 Series Cordless Phones Extra Device Ports (XDP) Support Expandable to 8 CO Lines and 16 Extensions 32 Station Capacity (max.) with XDP 1 Voice Mail Programmable Ports Automatic