Enterprise-Grade 3.5" Sata Hard Drive Ideal For Storage-Intensive Unifi Camera Security And Nas Systems. Workload Rating: 550 Tb/Year, Mean Time Between Failure (Mtbf): 2.5 Million Hours. Note. Verified And Optimized For Unifi Device Compatibility, May Include Hdds From Multiple Brands. Note. Please Note That You Cannot Order More Disks Than The Number Of Storage Bays Across All Consoles In Your Purchase.