The PCIX1PEX4 PCI-X to x4 PCI Express Adapter lets you install a low profile/half-height x4 PCI Express card into a full height PCI-X (3.3V, 64-bit) slot on a server or other high-end motherboard. With a physical x16 PCI Express female slot connector, the PCI-X to PCIe adapter card accepts all types of x16/x8/x4/x1 physical PCI Express cards (maximum speed of x4), allowing an older system to run the newest cards. Backed by a StarTech.com 2-year warranty and free lifetime technical support.