YUEYOU Super Speed PCI-E USB 3.0 Adapter 2 Port Express Card with 2 Internal USB 3.0 Ports 4-Pin Power Connector and 19-Pin Connector Super Speed USB 3.0 supports transfer speed of up to 5Gbps - The actual speeds limited by connected device's settings PCIe x 1 card with 2 external and 2 internal USB 3.0 ports Backwards compatible with USB 2.0 and 1.1 devices 4-pin DC connector to power USB devices from your PC power supply Support Windows XP/Vista/7/8(32/64 bit)