The SilverStone ECU04-E is a PCIe Gen 2.0 x2 expansion card with one internal 19pin USB 3.1 /3.2 connector (supporting two ports). It adds two redriver chips over the original ECU04 design for vastly improved performance over longer cable connections. This ensures dual 10Gbps bandwidth transfer rate can be maintained for up to 2 meters* compared with just 1 meter per USB 3.1's specified limitation. The ECU04-E is also backwards compatible with USB 3.0/2.0/1.1 and supports UASP (USB Attached SCSI Protocol) for enhanced performance. For operating systems with XHCI (extensible host controller interface), the ECU04-E will easily install without the need for any drivers because it also supports XHCI. For those looking to upgrade or add additional USB 3.1 / 3.2 ports or devices to their computer, The ECU04-E is a great starting point.