The Rosewill R2 is a dual bay RAID enclosure for two 3.5" SATA HDDs. It supports connectivity via USB or eSATA. With the included software you can create RAID 0, RAID 1 or JBOD arrays for increased performance or data safety. Since eSATA offers the same performance as you would see from an internal drive, the RAID 1 performance is very impressive with over 108 MB/s.