HDD 1.5 - 4TB WD Seagate 3.5" SATA Internal PC CCTV PS XBOX RRP x 5 | eBay
WD Blue 4TB PC Hard Drive - 5400 RPM Class, SATA 6 Gb/s, 256 MB Cache, 3.5 | 3600 EGP
Western Digital Purple 4TB Surveillance 3.5 Inch SATA 6 Gb/s Hard Disk Drive with Allframe 4K Technology - 180TB/yr, 64MB Cache, 5400rpm - WD40PURZ : Amazon.co.uk: Computers & Accessories