Add 4 Independent Super Speed USB (Universal Serial Bus) 3.0 ports to your PC through a PCI Express slot. The PEXUSB3S400 PCI Express USB (Universal Serial Bus) 3.0 Card adds 4 independent external USB (Universal Serial Bus) 3.0 ports to any PCI Express x 4-enabled computer system, with full bandwidth support (up to 5 Gbps) per port when connected to USB (Universal Serial Bus) 3.0 devices. Unlike other USB (Universal Serial Bus) 3.0 cards, which share the maximum bandwidth between multiple ports, the PEXUSB3S400 offers maximum transfer rates to each device when multiple devices are connected.