Ultra Aluminus USB 3.0 Dual Hard Drive Duplicator Dock - 2x 2.5&rdquo; or 3.5&rdquo; Drive Bays, Up to 4TB, SATA, Duplication and Erase, Brushed Aluminum Most standard drives 2 x 3.5" or 2.5" SATA HDD supported, each up 4TB Operates at USB 3.0 at Super(5Gbps) or High (480Mbps) or Full (12Mbps) speeds with backwards compatibility to USB2.0 and USB 1.1 SATA interface supports SATA - I/II/III HDDs Compatibility: Windows 7/8/XP/Vista and Mac OS X operating systems Two side anti-dust cover keeps docking shafts clean