Now Featuring RAID!, the Cavalry Storage Dual-Bay dock is perhaps the easiest and most cost-effective way to put your hard drives to work. This two-bay, hot-swappable USB 2.0 dock is the ultimate in versatility, featuring RAID, JBOD, and BIG/SPAN modes. In RAID mode, the dock automatically backs-up your data on the fly, making sure you have a copy of all your important data. In JBOD mode, your computer will recognize each hard drive as its own, independant volume. And with BIG mode turned on, your computer will read your two drives as one large volume. Switching between modes is a breeze - simply flip the switch in the back. The open air design allows easy access and fan-less ventilation to the hard drives ensuring your hard drives are safe, secure and accessible. This item comes with two 1TB (2TB totatl) high performance Hitachi hard drive with 32MB cache and a spindle speed of 7200RPM.