Quickly adds four USB 3.0 ports through an available PCI Express slot for connecting a variety of external USB devices Supports SuperSpeed USB 3.0 data transfer rates up to 5Gbps providing fast and smooth data transmission; Please note that the actual transmission speed is limited by the setting of the device connected. Supports UASP (USB Attached SCSI Protocol) and increases data transfer speed with external storage devices especially for SSDs Each port provides power output up to 900mA and features Over-Current protection to further protect your connected devices; EXTERNAL POWER CONNECTOR (Molex) NEEDED. Multi-port feature allows connecting several existing peripheral devices simultaneously and avoids frequent plug in and plug out