While I don't know the exact answer, I would hazard that its a basic 1TB sata drive from seagate. If you can get the drive out, it should just plug into your SATA ports.
I know from experience that a Western digital drive can be used this way as there is a USB to SATA adapter that needs to be removed before plugging it into the motherboard.
Yes it can be removed. All it is is a 1TB Seagate SATA drive, probably Barracuda. Not sure if it is 7200 or 5400. Inside the enclosure is simply a PCB with a chipset on it to convert SATA to USB.
A few days ago I took the 2.5" Seagate out of my FreeAgent Go and put it in my Macbook and it was a very smooth transfer. I even put my old Macbook drive back in the enclosure and it works fine and went back together without a hitch.