Seagate BarraCuda 4 TB 2.5 Inch Internal Hard Drive (15 mm Form Factor, 128 MB Cache SATA 6 GB/s Up to 140 MB/s) : Amazon.co.uk: Computers & Accessories
Seagate Barracuda 4TB HDD 2.5" 5400RPM SATA 128MB Cache Hard Drive - OEM (ST4000LM024) | OcUK
Internal 4TB + Hard Drives - HDD, SSHD at Overclockers UK
CAPHDD40TB72K35 - EMC 4TB 7200RPM SAS 6Gb/s 3.5-inch Hard Drive - iCityTech
320GB 1tb 2tb 4tb Internal Hard Drive Laptop PC 2.5' HDD SATA2 SATA3 8MB / 32MB 5400rpm-7200rpm 500GB 750GB HDD - China HDD and Hard Disk price | Made-in-China.com