Add four RS232 serial ports to any PC using a single PCI Express expansion slot. The PEX4S952 4 Port Native PCI Express RS232 Serial Adapter Card with 16950 UART allows you to turn a PCI Express slot into 4 RS-232 (DB9) serial connections. The four port serial card is based on a native single chip design, that harnesses the full capability of PCI Express (PCIe) - providing optimum reliability and speed, and reducing the load applied to the CPU by as much as 48% over conventional serial cards. Offering compatibility with a broad range of operating systems including Windows, Linux and Mac OS for easy integration into mixed environments. Plus, an included optional low profile/half-height bracket that allows the card to be installed in virtually any computer case - making it that much easier to add serial ports to your PCI Express enabled computer, regardless of the case form factor.