WD Ultrastar DC HC550 18TB SATA 6G 3.5" 7200RPM Enterprise HDD - WUH721818ALE6L4
[ G01-1631-5YR ] Western Digital Ultrastar DC HC550 WUH721818ALE6L4 18TB 7200RPM 256MB Cache SATA 6.0Gb/s 3.5" Datacenter Hard Drive (Certified Refurbished) - 5 Year Warranty. Why does helium make a di erence?.