StarTech.com 1-port PCI Express RS232 Serial Adapter Card - PCIe Serial DB9 Controller Card 16550 UART - Low Profile - Windows/Linux - 1 port PCI Express RS232 serial controller card w/16550 UART/ASIX MCS9922CV-AA - Bi-directional speeds 921.6Kbps/port | 256 byte FIFO | Pin 9 pwr out 5v/12v/none - Expansion card w/low profile (Std bracket incl) - Win/Linux The PEX1S553LP PCI Express Serial Card turns 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® and Linux Kernel 2.6.11 to 4.11.x, and ships with a low profile/half-height bracket installed, but includes an optional full 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 PEX1S552LP card. Backed by a StarTech.com 2-year warranty and free lifetime technical support. More from the Manufacturer