Iocell Networks 251U Traveler 2.5" USB 2.0 External HDD 500GB maximum storage capacity for expanded storage for your files. high-speed USB 2.0 interface USB-powered, so an AC adapter is not required for most computers. Backward compatible with USB data transfer rates up to 480 Mbps for quick response when updating files. Compatible with Windows, Mac and Linux or use with your existing computer.