WD Purple 6TB Surveillance Hard Disk Drive - 5400 RPM Class SATA 6Gb/s 64MB Cache 3.5 Inch WD60PURZ

Supports for more than 8 bays.
Supports up to 180 TB/year workload rate.
Engineered specifically for surveillance security systems.
Tuned for write-intensive, low bit-rate, high stream-count applications typical to most surveillance applications.
Prioritized write-operations for maximized surveillance performance.
TLER & ATA streaming support.
Tarnish-resistant components.
3-year limited warranty.