4TB Hard Drive optimized for 24/7 operation in WD Purple CCTV systems, 3.5 ”Surveillance Hard Drive, 4TB capacity, Cache 64MB, SATA III 6Gb / s interface, Sustained transfer rate 150MB / s, rotation speed 5900RPM. MTBF 1,000,000hours. 300 000 Load / Unload cycles. Workload 180TB / Year. Average power consumption 5.1W. Operating temperature 0 ° C ÷ 65 ° C, 3 years warranty.