Add 2 rs 232 serial ports to your standard or small form factor computer through a pci express expansion slot 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 the pex2s553 pci express serial card lets you turn a pci express slot into 2 rs232 db9 serial ports'. '.strtoupper('b')ased on a native single chip design no bridge chip, this 2 port serial adapter card allows you to harness the full capability offered by pci express pcie, and reducing the load applied to the cpu by as much as 48% over conventional serial cards'. '.strtoupper('t')he rs232 serial adapter card pex2s553 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, and mac os 10.4 and above'. '.strtoupper('p')lus, the serial card includes an optional half height low profile bracket that allows the card to be installed in any pci express slot, regardless of the size of the computer case'. '.strtoupper('t')his product is a replacement for our pex2s552 card'. '.strtoupper('b')acked by a startech.com lifetime warranty and free lifetime technical support'. '.strtoupper('w')hats in the box 2 port pci express serial card low profile brackets driver cd instruction manual