Free Shipping! WD 18TB Storage Capacity, 3.5" Form Factor, SATA III 6 Gb/s Interface, 512MB Cache, 7200 rpm, Up to 269 MB/s Data Transfer Speeds, 2.5 Million Hour MTBF, HelioSeal Technology, 600,000 Load/Unload Cycles, 0.35% Annualized Failure Rate (AFR)