Digital Storage Capacity: 4.0 TB hard drive provides ample storage space for your data. Compatibility: SATA hard drive is compatible with most desktop computers. Portability: Compact 3.5-inch form factor allows you to take your data on the go. Rotation Speed: 7200 RPM ensures fast data transfer rates. Mechanical Hard Disk: Durable mechanical design provides reliable data storage. The Hitachi Deskstar 5K4000 hard drive provides an enormous 4TB capacity and features innovative CoolSpin technology to deliver a greater level of power efficiency and quiet operation for energy-conscious, environmentally-friendly computers. This 4TB hard drive uses Advanced Format, which increases the sector size on HDDs from 512 bytes to 4096 (4K) bytes, thereby increasing capacities and improving error correcting capabilities.