Panasonic KX-TES824 advanced hybrid telephone system - up to 24 extensions. The KX-TES824E is initially configured to 3 exchange lines and 8 extensions. With optional cards you can easily expand the capacity up to 8 exchange lines and 24 extensions. The system comes with built-in DISA / Message on busy, Extension Caller ID, Remote Modem and USB Port for PC Programming.