The hardware:

When I first saw the pictures of the X-Duo on the Thermaltake website, I thought it looked kind of big, but once I took it out of the package, I was pleasantly surprised just how diminutive the unit really is.  The unit measures 4.5" wide, 6" tall, and 9.5" deep. 

Other than the front of the unit, the rest is a fairly non-descript gray; great for hiding it out of the way.

The rear of the unit houses all of the ports and the fan.  From top to bottom, we can see the power switch, power plug, Gigabit LAN port, and two USB ports.  The drives themselves are cooled by a small 60mm fan. 

The bottom of the unit utilizes four durable feet for the unit to stand on. 

The enclosure includes: a power cable with transformer, a bag of screws, two drive rails, an installation manual, a software CD, and an ethernet cable.

For the testing, I have acquired two Samsung HD753LJ 750GB hard drives.  I used these drives for their reputation for noise, heat, and reliability.  Performance is still important, but in terms of data backup, is of less significance than if I was choosing drives for my gaming rig.

Two install the drives, the first step is to pry off the front cover.  Here, I have elected to use a small screwdriver to do the job.

Once the cover is removed, we have full view of the interface for the drives.  Notice the rails that sit on the top and bottom of the enclosure.

Next up, we use the included screws to attach the rails to the hard drive.  Notice the handle that sits out in front of the drive.  Screws are also attached to the bottom, and act as guides for the rails.

Once the rails are attached, the drive slides directly into the enclosure until the rail clicks into place. 

Wash, rinse and repeat with a second drive, and you are all set.  The only thing left to do is to re-attach the cover.