UtechSmart USB 3.0 4 Port Hub for Ultra Book, MacBook Air, Windows 8 Tablet PC, Backward Compatible with USB 2.0 Special for Laptop, Ultrabook, tablet PC and PC. Compact and portable. 4-Port USB 3.0 Hub at 5.0Gbps - backwards Compatible with USB 2.0 and 1.1 devices Plug and play - does not require any software, drivers, or complicated installation process. The connection cable is attached to the hub -no need to worry about leaving it behind or losing it. Bus Powered - does not require an AC adapter - compatible with Microsoft Surface, Ultrabooks and MacBook Air