Full Details from Amazon.com : http://www.amazon.com/gp/product/B00535BUR4?tag=onigi-20
StarTech.com 4-Port Native PCI Express RS232 Serial Adapter Card with 16550 UART (PEX4S553)
Native single-chip single lane PCI Express chipset delivers true PCIe performance up to 48 more efficient than bridge chip designs
Standard and low profilehalf-height brackets included to ensure fitment in any system
Four high speed RS232 serial ports with support for data transfer rates up to 128000bps
Built-in 16C450550 compatible UART
Includes half-heightlow profile mounting brackets
256-byte deep FIFO per transmitter and receiver