Free Express Shipping! WD 4TB Gold 7200 rpm SATA III 3.5" Internal Enterprise HDD 4TB Storage Capacity, 3.5" Form Factor, SATA III 6 Gb/s Interface, 256MB Cache, 7200 rpm, Data Transfer Speeds up to 267 MB/s, 600,000 Load/Unload Cycles, 2 Million Hours...