The WD Red Pro series is designed for small and medium-sized businesses and is available for medium to large NAS environments with up to 24 bays. WD Red Pro drives are designed to handle increased workloads in your business, have undergone extensive testing, and are backed by an extended five-year limited warranty . Why WD Red Pro • Western Digital quality proven over the years • High mean time between errors • Shock protection • High capacity • 5 year warranty Key Features • Capacity: 4 TB • Interface: SATA III (6 Gb/s) • Disc rotation speed: 7200 rpm • Cache: 256 MB • Disc format: 3.5" • Max