The OWC ThunderBay 4 is a Thunderbolt 2 hard disk enclosure that holds up to 4 drives. The enclosure does not have hardware RAID support (although this is possible with software) and the disks appear individually to the operating system. In other words this is a JBOD ("just a bunch of disks") enclosure. Note that the "ThunderBay 4" is an updated version of the "ThunderBay IV" enclosure. The primary (and perhaps only) difference is that the enclosure now supports Thunderbolt 2 connections. I ...