Seagate SV35 2TB 7200RPM SATA 6-Gb/s NCQ 64MB Cache 3.5-Inch Internal Bare Drive for Video Surveillance ST2000VX000 Ideal for entry-level surveillance DVRs Capacities up to 3TB support systems with 1-8 drive bays and up to 32 cameras Precision-tuned for high write surveillance workloads For additional features to support NVR applications check out Seagate Surveillance HDD