Amazon.com: Western Digital WD4000FYYZ ENTERPRISE 4TB 7200RPM 64MB Cache SATA 6.0Gb/s 3.5 internal hard drive
Amazon.com: Seagate BarraCuda Pro 4TB Internal Hard Drive Performance HDD – 3.5 Inch SATA 6 Gb/s 7200 RPM 128MB Cache for Computer Desktop PC, Data Recovery (ST4000DM006) : Electronics