Capacity:4TB | Style:New Generation Surveillance HDD WD Purple drives are built for 24/7, always-on, high-definition security systems. With a supported workload rate1 of up to 180 TB/yr. and support for up to 64 cameras, WD Purple drives are optimized for surveillance systems. WD Purple surveillance storage also comes with WD's exclusive All Frame 4K technology, so you can confidently create a security system tailored to the needs of your business. Using All Frame 4K technology, WD Purple drives improve ATA streaming to help reduce errors, pixilation, and video interruptions that could happen in a video recorder system. 1Workload Rate is defined as the amount of user data transferred to or from the hard drive. Workload Rate is annualized (TB transferred ✕ (8760/recorded power-on hours)). Workload Rate will vary depending on your hardware and software components and configurations.