WD Red™ Pro 4TB 3.5" Internal Hard Drive For NAS, 64MB Cache, SATA/600, WD4001FFSX

Joining the original color of NAS, WD Red Pro continues the formula of success that has led the WD Red product family by adding support beyond consumer and small business markets into medium and large 8-16 bay business storage systems. WD Red Pro hard drives integrate WD's exclusive technology, NASware, to provide unparalleled support for drive compatibility, reliability, and performance.