"Add a high-speed RS-232 Serial port to your computer through a PCI Express expansion slot
The PEX1S553 PCI Express Serial adapter card allows you to turn a PCI Express slot into an RS232 (DB9) serial connection. The card is constructed using a native single chip design that lets you harness the full capability offered by PCI Express (PCIe), while reducing the load applied to the CPU by as much as 48% over conventional bridge chip serial cards.
The PCI Express (RS232) Serial Adapter Card is compatible with a broad range of operating systems including Windows® 2000/XP/2003/Vista™/Windows 7/Server 2008 R2 (32 and 64 bit), Linux Kernel 2.6.11 and up, as well as MAC OS X 10.4 and above. The adapter card includes an optional half-height/low profile bracket, that lets you add a serial port to virtually any computer, regardless of the case form factor.
This product is a replacement for our PEX1S552 card.
Backed by a StarTech.com Lifetime warranty and free lifetime technical support."
" * Native single-chip, single lane PCI Express chipset delivers true PCIe performance
* Standard and low profile/half-height bracket included to ensure fitment in any system
* Easy to install and use with full step-by-step instructions saving time and hassle"

Specifications