P20U/P51U: The Shuttle XPC all-in-one P20U/P51U Series comes with two COM ports as standard. The PCP11 adds up to two more COM ports which makes it a total of four serial COM ports (RS232) with Sub-D connectors.
DS10U: The Shuttle XPC slim DS10U Series comes with one COM Port and one VGA port as standard. If two COM ports are required, the existing VGA port may be removed and replaced by PCP11 instead.