Add 2 high speed rs 232 serial ports to your low profile small form factor computer with a pci express expansion slot native single chip, single lane pci express 48% less cpu load, and increased performance pre configured with half height mounting bracket for low profile systems, but includes a full profile bracket for versatili easy to install and use with full step by step instructions saves time and hassle the pex2s553lp low profile half height pci express serial card turns a pci express slot into two rs232 db9 serial connections'. '.strtoupper('t')he 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'. '.strtoupper('t')he 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, and ships with a low profile half height bracket installed but includes an optional full profile bracket that lets you add 2 serial ports to virtually any computer regardless of the case form factor'. '.strtoupper('t')his product is a replacement for our pex2s552lp card'. '.strtoupper('b')acked by a startech.com lifetime warranty and free lifetime technical support'. '.strtoupper('w')hats in the box pci express serial card db9 ribbon cable full profile bracket low profile bracket driver cd instruction manual