Good sturdy 4tb hard drive from reputable brand.
Price has fluctuated a lot recently having jumped from £110 up to £140-150.
This is the lowest I've ever personally seen them.
Drive can be removed with a bit of forcehttp://www.youtube.com/watch?v=morhgz2OU_g
Internal drive is a 5K4000 - HDS5C4040ALE630
I currently have 10 of these in a RAID Z2 array and they haven't skipped a beat.
And on Friday I'll have 20 :-)
If you buy multiple then the DABS Xmas codes work
XMASSAVE10 for £199 or over
XMASSAVE25 for £399 or over
XMASSAVE40 for £599 or over