WD Blue WD20SPZX 2 TB 2.5 Internal Hard Drive – SATA – 5400rpm – 128 MB Buffer

WD Purple WD22PURZ – hard drive – 2 TB – SATA 6Gb/s

WD Blue WD30EZAZ – Hard drive – 3 TB – internal – 3.5 – SATA 6Gb/s – 5400 rpm – buffer: 256 MB

WD Purple WD30PURZ – hard drive – 3 TB – SATA 6Gb/s

WD Red WD40EFAX 4 TB Hard Drive – 3.5 Internal – SATA (SATA/600) – Storage System Device Supported

WD HDD Int 4TB Red Plus SATA 3.5