(Old Model) Seagate 4TB Surveillance HDD 6Gb/s Internal Hard Drive (ST4000VX000) Ideal for surveillance DVRs and NVRs Capacities up to 8TB support systems with 8+ drives and 64 cameras per drive Precision-tuned for high write surveillance workloads Workload rating of 180TB/year offers 3x the support of a desktop drive Reliably performs in multi-drive systems with RAID support