WD Purple 1TB Surveillance Hard Disk Drive - 5400 RPM Class SATA 6 Gb/s 64MB Cache 3.5 Inch - WD10PURX [Old Version] Engineered specifically for surveillance security systems Reduced video frame loss 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. Package includes a hard drive only - no screws, cables, manuals included. Please purchase mounting hardware and cables separately if necessary. Ships in WD-certified box for safe transit during shipping