This WD Red 4TB Internal Hard Drive is designed to withstand the strenuous 24-hour operating environment found in most NAS systems. It contains advanced firmware technology that enables seamless integration, enhanced data protection and optimal performance for systems operating in NAS or RAID environments. The NAS hard drive comes complete with standard features such as a SATA 6Gb/s interface, IntelliPower rotational speed and a 64MB cache memory buffer. The NASware 2.0 firmware, which is offered by free download, optimizes the drive to operate in NAS environments by reducing noise and power consumption, providing tools to resolve issues, limiting vibration and permitting a lower operating temperature. This 2.5" hard drive is NAS-compatible and protects your data even in the event of a power loss or power disruption. This device is ideal for consumers or small businesses with one- to five-bay NAS units where you can install or upgrade to the full 4TB maximum.