Amazon.com: Western Digital Purple 4TB Surveillance Hard Disk Drive - 5400 RPM Class SATA 6 Gb/s 64MB Cache 3.5 Inch - Western Digital40PURZ [Old Version] : Electronics
4TB Western Digital Purple Hard Drive
WD40PURX-64GVNYO Western Digital Purple 4TB 5400RPM SATA 6Gbps 64MB Cache 3.5-inch Internal Hard Drive