2S1P PCI Express Serial Parallel Combo Card with Breakout Cable. The PEX2S1P552B PCI Express Serial/Parallel Combo card combines the functions of a PCI Express Parallel Card and PCI Express Serial Card, for installation in a single PCIe expansion slot. A suitable addition to small form factor cases, the card offers a low profile design and includes an optional full profile bracket. The card features a single parallel/serial combo port that delivers individual parallel and serial connections using the included break-out style cable - adding two RS232 DB9 serial ports and one parallel port while avoiding "crowded" connections that can occur with fixed/static connection ports. The adapter card features a native PCI Express single-chip design that allows you to take advantage of full PCI Express capability, providing improved system and peripheral speed and reliability while reducing the load applied to the CPU by as much as 48% over conventional bridge chip adapter cards