The WD RE 4TB SAS hard drive is a high-performance storage solution designed for server use. With a rotation speed of 7200 RPM and a cache size of 32MB, this Western Digital drive offers fast data access and transfer The 4TB storage capacity provides ample space for storing large amounts of data, while the RAID server functionality enhances data reliability and security. Ideal for businesses and professionals looking for dependable and efficient storage solutions. This is a LOT of THREE HDD's