The ToughArmor MB516SP-B fits in only two 5.25" bays, making it perfect for high density storage applications. It features the unique EZ-Slide Nano trays that make installing drives a snap. Its large user-controllable fan runs quietly, utilizing its many ventilation holes for maximum airflow at minimal RPM ranges. The fan has 3 modes the user can set; high, low, and off. The MB516SP-B features a rugged heavy duty full-metal housing designed to meet high IOPS requirement which are generally found in enterprise environments, military systems, medical systems, high performance computing and industrial settings.