Seagate NAS HDD ST4000VN000 4TB 5900 RPM 64MB Cache SATA 3.0Gb/s 3.5" Internal Hard Drive - Newegg.com
Seagate ST4000VN000 4TB SATA 3.5 6Gb/s 5900RPM NAS Hard Drive 1H4168-505 | eBay
Amazon.com: Seagate 4TB IronWolf NAS SATA Hard Drive 6Gb/s 256MB Cache 3.5-Inch Internal Hard Drive for NAS Servers, Personal Cloud Storage (ST4000VN008) : Electronics