WD Purple 4 TB Surveillance Systems Purple SATA Internal Hard Disk Drive (HDD) (WD42PURZ -256 MB Cache)  (Interface: SATA, Form Factor: 3.5 inch)

The WD Purple surveillance storage is built to handle up to 64 cameras per drive and is designed for 24/7, always on, high-definition surveillance security systems with more than eight bays. With a wide range of industry-leading enclosures and chipsets supported, you're sure to find the configuration and compatibility that's right for your NVR. Low power consumption is a must in a high-temperature, always-on surveillance environment. Intelliseek technology helps reduce damaging ambient noise and vibrations.