SIIG's USB 3.0 external hard disk drive dock, the SuperSpeed USB 3.0 to SATA 3Gb/s Dual Docking, is an excellent product designed to add high capacity mobile storage devices to your USB 3.0-equipped desktop or notebook computer. It allows you to quickly connect and access your SATA hard disk drives without having to open your computer case or storage enclosure. This SuperSpeed USB 3.0 to SATA 3Gb/s Docking features two hard disk drive docking bays to support 2.5" or 3.5" SATA hard disk drives with capacity up to 2TB, an ideal design for disk to disk backup. It comes with a built-in cooling fan for lowering operating temperature to extend hard disk drive life and delivers SuperSpeed USB 3.0 data transfer rates of up to 5Gb/s, 10x faster than USB 2.0. It is the high performance storage solution for super fast accessing, transferring and backing up large data files between your external storage device and your USB 3.0 equipped desktop or notebook computer.