Hgst NAS 4 TB Desktop SATA Internal Hard Disk Drive (HDD) (Deskstar NAS Drive)  (Interface: SATA)

HGST (Hitachi+WD) is a WD Company .. and Hitachi is the best Manufacturer ..in HDD Market .. believe it or not, HGST HDDs lasts Longer than any other HDDs.
As HDD survey proved that seagate is a shit and then WD is awesome because seagate's HDD failure rates are above 15 % whereas WD's HDD failure is only from 3-5 % and at the last HGST or Hitachi's HDD failure rate is only 0.9-1.5 % ..
And it's been proved that 3 TB HDD does not last longer than 4 TB .... So go for this Drive :-) .

7200 RPS, 4TB HDD.

Works just fine, fast and temperature is surprisingly low for most of the time. All other high capacity drives from crap companies like WD and Seagate fail. This NAS drive is designed to be used heavily. No data loss, no problems.