WD RE4 7200 RPM Enterprise SATA hard drives offer capacities up to 2 TB, loaded with performance and reliability features ideal for servers, video surveillance, and other demanding write-intensive applications. With a designed, manufactured and demonstrated MTBF of 1.2 million hours at 100% duty cycle in nominal enterprise conditions, 64 MB cache, and best-in-class vibration tolerance, these drives are the ultimate in Enterprise SATA storage. Backed by a 5-year limited warranty.