Startechcom 2 port pci express pcie to rs 232 serial cards startechcom pex2s553s the startechcom pex2s553s 2 port pci express serial card lets you add two esd protected rs232 ports with 5v or 12v selectable power output ideal for industrial environments this 2 port serial card offers built in 15kv esd protection which helps prevent damage to connected devices in the event of line surges and electro static discharge an extended operating temperature range 30degc to 75degc also hel