WD Red Pro 12TB SATA III 3.5″ Internal NAS HDD, 256 MB Cache, 7200 RPM Speed, Up to 217 MB/s Sustained Transfer Rate, NASware 3.0 Technology 1 Million Hours MTBF | WD121KFBX

Available in capacities ranging from 2 to 22TB(1) with support for NAS systems with up to 24 bays | (1) 1GB = 1 billion bytes and 1TB = 1 trillion bytes. Actual user capacity may be less depending on operating environment. Supports up to 300TB/yr workload rate(2) | (2) Workload Rate is defined as the amount of user data transferred to or from the hard drive. Workload Rate is annualized (TB transferred ✕ (8760 / recorded power-on hours)). Workload Rate will vary depending on your hardware and software components and configurations. Enhanced reliability with 3D Active Balance Plus technology and error recovery controls with NASware 3.0 technology Extended drive testing to ensure each drive is tested for extended reliable operation SKU: SKU-18E121D2 Category: Internal Hard Drives Brand: Western Digital