Add 5 USB 3.0 ports to your computer * SuperSpeed USB 3.0 supports transfer rates of up to 5Gbps - The actual transmission speed is limited by the setting of the device connected and your pc hardware * Backwards compatible with USB 2.0 and 1.1 devices; Operating System Compatibility: Windows XP, Vista, 7, 8 . Bracket Size: 12 CM * 5V 4 pin connector to power USB devices from your PC power supply; The PCI-E Port only support PCI-E X1/X16 slots. * Free lifetime technical support and 24 Month Warranty