WD TDSourcing Red Pro NAS Hard Drive WD4001FFSX - Hard drive - 4 TB - internal - 3.5" - SATA 6Gb/s - 7200 rpm - buffer: 64 MB - for WD My Cloud EX4
WDRedProNASHardDriveWD4001FFSX-Harddrive-4TB-internal-3.5\"-SATA6Gb/s-7200rpm-buffer:64MB-forWDMyCloudEX4