4TB SATA HUS724040ALE640 Hitachi 3.5in Desktop Hard Drive | 7.2K RPM 6Gbps 64MB
Amazon.com: HGST Deskstar NAS 3.5-Inch 4TB 7200RPM SATA III 64MB Cache Internal Hard Drive Kit (0S03664) : Electronics
HGST MegaScale DC 4000.B HMS5C4040BLE640 (0F23139) 4TB Coolspin 64MB Cache SATA III 6.0Gb/s 3.5" Enterprise NAS Hard Drive - w/3 Year Warranty - Walmart.com