WD Purple 6TB Surveillance Internal Hard Disk Drive

Form factor: 3.5-inch Interface: 6.0 Gbit/s Capacity: 6 TB Rotational speed: IntelliPower * Buffer size: 64 MB Load/unload Cycles: 300,000 minimum Buffer To Host (Serial ATA): 6 Gb/s (Max) Host to/from drive (sustained): 175 MB/s Performance class: 5400 RPM