Add 2 high-speed RS-232 serial ports to your low profile/small form factor computer with a PCI Express expansion slotThe PEX2S553LP low profile/half-height PCI Express Serial Card turns a PCI Express slot into two RS232 (DB9) serial connections.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® 2000/XP/2003/Vista™/Windows 7/Server 2008 R2 (32 and 64-bit), 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 2 serial ports to virtually any computer (regardless of the case form factor).This product is a replacement for our PEX2S552LP card.Backed by a StarTech.com 2-year warranty and free lifetime technical support.