Western Digital Ultrastar DC HC550 16TB 3.5 SATA 6Gb/s Enterprise Hard Drive, 7200 RPM, 512MB Cache, CMR, Energy-Assisted Magnetic Recording (EAMR), Triple-Stage Actuator, HelioSeal Helium-Sealed, 262 MB/s Transfer, 2.5M Hours MTBF, 550TB/Year Workload