WD Red Pro 3.5" NAS Hard Drive WD141KFGX - Hard Drive 14TB - SATA 6 Gb/s. 3.5-inch form factor. Interface Rate 255 MB/s. 7200 RPM class. 300 TB Workload Rate. 512 MB Cache. Medium to large NAS systems with up to 24 bays. For systems that use 1-8 bays, please consider WD Red hard drives. 5 Year limited warranty. SINGLKE PACK