Western Digital Purple 3TB HDD OEM Tuned for write intensive, low bit rate, high stream count applications typical of most surveillance applications SATA interface with 6 GB/s and 64 MB cache Optimized with AllFrame 4K technology Monitoring 3.5 inch hard drive Overview built for 24/7, always ready, high quality Nition security systems. With a supported workload rate of up to 180 TB/year and support for up to 64 cameras, WD Purple drives are optimized for surveillance systems. Designed for compatibility. WD Purple surveillance hard drives are built for compatibility with industry-leading chassis and chipset manufacturers to enable seamless integration with your new or existing video surveillance system. Optimized performance for up to 64 cameras with support for up to 64 surveillance cameras per hard drive, WD Purple gives you the flexibility to update and expand your security system in the future. Peace of mind surveillance memory WD Purple surveillance hard drives are designed for high-temperature, continuous surveillance security systems to ensure reliability and high-quality video playback when you need it most. Specifications Cache Installed size: 256 - Digital storage capacity: 3 TB - Hard drive speed: 5400 rpm - Hard drive form factor: 8.9 cm - Hardware connectivity: SATA 6.0 Gb/s - Item dimensions: 4 5.79 2.6 cm - Item weight: 0.6 kg