2 Ports RS232 RS422 RS485 Combo  (16C950)PCI Express  PCIe Card & Low Profile Bracket LP

PCI-e one chip solution(Pericom  PI7C9X7952)

It's real COM Port in your computer, not USB to COM port
  high compatible with serial type device.

2 Ports RS232/422/485 (Software Control)

Fully compliant with PCI Express Card Specification 1.1

Two 16C950 UART Serial Ports

128-byte assigned FIFO

4-wire RS-422/485 and 2-wire RS-485 applications

RS232 Speed up to 230kbps

RS422/485 Speed up to 115.2Kbps

OS Support:

Windows® 2000, XP, Server 2003 ,Vista, Linux  kernel  2.6.x

Accessories:

1 x Manual, 1 x Driver CD

1x  2nd Serial port Cable with Low Profile Bracket