WD Purple 1TB 64MB 3.5" SATA HDDWD 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. Engineered for compatibility WD Purple surveillance hard drives are built for compatibility with industry leading chassis and chip set manufacturers for seamless integration into your new or existing video surveillance system. Optimized performance for up to 64