Panasonic KX-TD170 8-Port Analog & Digital Station Expansion Car

KX-TD170 adds 8 multi-line digital extensions Plus 8 single-line analog ports. It is a large expansion board that attaches to the front door, with a flat ribbon cable that goes through the door and plugs into a connector on the front panel of the control unit. Phone connections are on a 25-pair female Amphenol connector.

For KX-TD816 and KX-TD1232. The KX-TD1232 can use two; the KX-TD816, just one.