The 4x WD Red Pro 3.5" SATA III Internal Desktop NAS Hard Drive Bundle includes four high-performance drives backed by a WD 5-Year Limited Warranty. These drives are specifically designed for Network Attached Storage (NAS) environments, especially multi-bay systems, offering greater reliability than standard desktop hard drives. With a 3.5-inch form factor, they are compatible with most NAS enclosures and desktop bays. Each drive features a SATA III interface, supporting data transfer speeds up to 6 Gb/s, and belongs to Western Digital's Red Pro Series, tailored for enterprise-level, 24/7 operation. Operating at 7200 RPM and typically equipped with large caches, these drives deliver superior performance for demanding tasks. They\u2019re built for high endurance and reliability, with robust ratings for workload and Mean Time Between Failures (MTBF). To maintain performance in multi-drive setups, the drives include multi-axis rotational vibration (RV) sensors, helping preserve data integrity. Optimized for RAID environments, they ensure efficient and secure data handling, and they use Conventional Magnetic Recording (CMR) technology to support consistent and reliable write performance under sustained workloads