I don't think it is a dual disk, I believe that model is the new 12.5mm 2TB drive recently released. It COULD be a 15mm drive, though. I sacrificed a Seagate 1.5tb drive to put into my HP Pavilion 2 drive laptop, a close fit (the drive panel underneath bulges a little) but has been working fine for a week. And I now have 2 tb of space (500gb and the 1.5gb drives).
I'm looking for something bigger, and the WD model listed above could be the ticket, but only because a 12.5mm drive barely fits my laptop.
Everyone else is right, the ONLY 9mm drives available in TB range are 1tb at 5400 RPM.
If you just want an external and USB only powered that might do the trick.
- Qlippoth