WD Red Pro 20TB NAS 3.5" Internal Hard Drive - 7200 RPM Class, SATA 6 Gb/s, CMR Recording Technology, 512MB Cache

Available in capacities ranging from 2 to 22TB(1) | (1) 1GB = 1 billion bytes and 1TB = 1 trillion bytes. Actual user capacity may be less depending on operating environment. For RAID-optimized NAS systems with unlimited number of bays Rated for 550TB/yr workload rate(2) | (2) Annualized Workload Rate = TB transferred x (8760 / recorded power-on hours). The maximum rated workload is specified for operating at typical temperature of 40C. Workload Rate will vary depending on your hardware and software components and configurations. Designed to handle the demands of high-intensity 24x7 multi-user NAS environments Western Digital partners with a wide range of NAS system vendors for extensive testing to ensure compatibility with most NAS enclosures