Well made fanless enclosure.
If you intend to use this with a Linux based NAS and a large (>2TB drive) then the following may help.
As confirmed by the German manufacturer (Raidsonic), in an email I received from them, this will work with a 3TB drive (and I guess probably a 4TB but I can't confirm this). However, they didn't tell me how to set it up but I managed to work it out. I went for the Seagate Barracuda 7200 [...] as the Hitachi drive in the QNAP seems a bit noisy.
However, on installing the drive (easy although you have to pull on the door rather hard to remove the drive) both my MacBook Pro (early 2011, Mountain Lion) and my QNAP P119II both saw the drive as 800GB or so rather than the expected 2.7TB. OS X Disk Utility was no better no matter how I formatted it. I solved the problem using Linux running on the QNAP and controlled through OS X Terminal. I followed [...] after making sure that I was formatting the correct disk. I had to reboot the NAS with the enclosure attached by eSATA the first time for it to be recognised (further reboots don't seem necessary). Now the QNAP finds it in seconds. USB2 connection is fine if slow in comparison with the eSATA interface.
I've seen plenty of other alternative solutions on Windows boxes but luckily didn't have to wrestle with drivers and BIOS settings. The Seagate website goes into glorious detail for Windows users but was silent when it came to my setup.
You get both eSATA and USB cables and a GB switched mode plug in the box, as well as a removable hoop to stand the drive upright.
This combination now more or less silently backs up my NAS data over eSATA. A 1.3TB backup took about 7 hours. The fanless case got warm but not hot.
I hope that this helps others with a similar problem to solve.