WD SE 4TB Datacenter Hard Disk Drive - 7200 RPM SATA 6 Gb/s 64MB Cache 3.5 Inch - WD4000F9YZ Cost-effective per GB StableTrac and RAFF for enhanced vibration tolerance Best-in-class Performance Maximum capacity 5-year manufacturer limited warranty Package includes a hard drive only - no screws, cables, manuals included. Please purchase mounting hardware and cables separately if necessary. Package includes a hard drive only - no screws, cables, manuals included. Please purchase mounting hardware and cables separately if necessary. Cost-effective datacenter storage delivers the right blend of performance, reliability and capacity and keeps your total cost of ownership low. All drives undergo at least 5 million hours of functional testing, and over 20 million hours of additional testing under actual workloads in actual server and storage systems. Enhanced Rotary Acceleration Feed Forward technology results in a significant performance improvement in high vibration environments over the previous generation of drives. 4 TB capacity holds up to 800,000 digital photos, 1,000,000 MP3 files, and 300 hours of HD video. 5 year limited warranty.