In the 5TB version is currently (04/2015) a WD50EZRX (WD Green 64MB cache, 7200 U / min) installed. I was hoping for a EFRX (RD Red), but you can not have everything. The case is unfortunately a little difficult destructively open, with the correct YouTube video but no problem. Whether the housing is reusable for another hard disk, to be seen. If not, then it does not matter, because the bare disk is more expensive than the WD Elements. Either way, the housing is definitely lifted in order to have complete your repair the unit.