Add two PCI & two PCI Express expansion card slots to your desktop computer. The PEX2PCIE4L PCI/PCI Express Expansion Chassis provides a quick & simple I/O expansion solution to almost any PCI Express (PCIe) enabled system. Adding PCI/PCIe cards to a server or workstation, or providing a platform to swap cards between a mobile & desktop setup is a cost-effective & time-saving solution for maximizing the I/O capabilities of your system. The external expansion chassis adds two full-length (38cm) PCI slots (32-bit/33 M Hz), as well as two PCIe x 1 (single-lane) slots to a host computer through a single PCI Express connection. Providing total bandwidth up to 250 M Bps from the PCIe x 1 host controller card allows the computer to function as though the expansion chassis cards were connected directly to the motherboard.