WD Red 3.5" NAS Hard Drive WD140EFFX - Hard Drive 14TB - SATA 6 Gb/s. 3.5-inch form factor. Interface Rate 210 MB/s. 5400 RPM class. 180 TB Workload Rate. 512 MB Cache. WD RedTM NAS hard drives are designed and tested for use in up to 8-bay NAS systems. 3 Year limited warranty. SINGLE PACK