The 4-Port Native PCI Express RS232 Serial Adapter Card with 16550 UART lets you add 4 RS232 (DB9) serial ports, using a single PCI Express expansion slot. Based on a native single-chip design, this 4-port serial adapter card allows you to harness the full capability offered by PCI Express (PCIe), while reducing the load applied to the CPU by as much as 48 percent over conventional bridge-chip serial cards. The RS232 Serial Adapter Card includes 4 half-height/low-profile brackets, allowing the card to be installed into almost any PC case, regardless of form factor.