The PEX2S553LP Low Profile/Half-Height PCI Express Serial Card allows you to convert a single PCI Express slot into two RS232 (DB9) serial connections.The card is manufactured with a native single-chip design that takes full advantage of the potential of PCI Express (PCIe) while reducing the load on the CPU by as much as 48% over traditional serial cards (bridge chip).The PCI Express RS232 Serial Adapter Card is compatible with a wide range of operating systems including Windows 2000/XP/2003/Vista/Windows 7/Server 2008 R2 (32-bit and 64-bit), Linux Kernel 2.6.11 and higher, and comes with a Low Profile/Half-Height bracket installed but includes an optional Full Profile bracket that allows you to add 2 serial ports to virtually any computer (regardless of case form factor). Features: One high-speed RS232 serial port with data transfer rate up to 460.8 Kbps Comes with half-height/low-profile mounting bracket, includes optional standard profile bracket Single-chip design optimizes speed and reliability Single, native PCI Express lane chip 9-pin serial port power selector for output Compliant with PCI Express Base Specification, Revision 1.1a Automated out-of-band flow control using CTS/RTS/DTR and DSR Automated software programmable flow control with in-band XON/XOFF in both directions 128-byte FIFO depth per transmitter and receiver