It's an Addonics ST6ESA Storage Tower. You can get their storage towers with a wide variety of different "backplates" that provide different types of connectivity. They have them listed here:
http://www.addonics.com/products/raid_system/ast4-withoutST.aspI got the one with the 6 separate eSATA ports, rather than a port multiplier one, because I wanted to make sure I could get the best possible performance out of the box. They even have versions with infiniband if you want to get crazy. This particular storage tower has 4 5.25" bays, just like a regular PC case. You can add up to 4 hard drives via normal 3.5" -> 5.25" mounting brackets. If you want to add 6 drives instead, you can add two of the
Disk Array 3SA devices, which expands it up to 6 disks and provides additional cooling (since it is a pretty standard case inside, you could also probably figure out a way to mount the 6 drives in there without the add-on, but then you might want to cut out a side panel and add a fan to prevent heat build-up.
Addonics has TONS of options, though...
They have the
Storage Rack that is a 4U Server sized box that has 9 5.25 bays (supporting up to 15 3.5" disks with a bunch of add-on Disk Array 5SA devices) and has all kinds of connectivity options. They also have the
Mini Storage Tower, which uses 3.5" drive bays instead and is a bit smaller if you don't need the extra space; or a whole line of
different sized 5.25" Storage Towers. They all have user-configurable back-plates. Also, the back-plates can be bought separately, so you can go with 6x eSATA now, and then swap it out for an Infinband port later on if you want.