WD 20TB Enterprise Class SATA HDD. 3.5" 18TB, SATA 6 Gbs, 7200 RPM Class, Cache 512MB. Conquer tough workloads with enterprise-class WD Gold HDDs. Available in 1TB to 18TB capacities, this highly reliable solution for demanding storage environments provides up to 2.5M hours MTBF, vibration protection technology and a low power draw thanks to HelioSeal technology [for 12TB and above]. Specifically designed for use in enterprise-class data centers and storage systems, the WD Gold SATA HDD delivers the world-class performance you expect from Western Digital hard drives. 5-Year Limited Warranty Every WD Gold HDD comes with a 5-year limited warranty, so you can be confident in your storage *** SINGLE PACK ***