Silverstone Dual Bay USB 3.0 SuperSpeed 3.5 Inch External Hard Drive Enclosure with RAID DS321B - Black Configurable RAID function (Non-RAID, RAID 0, RAID 1) Supports large volumes in excess of 2TB USB 3.0 Super Speed connection Backwards compatible with USB 2.0 Hi-Speed connection Compact and screw-less design for easy HDD installation Built-in low speed (2800RPM) fan for extra cooling Security lock slot