The HGST Ultrastar internal hard drive kit delivers colossal add-on storage and performance with an industry-standard SATA 6 Gb/s interface. This solution is perfect for RAID arrays, Disk to disk backup and archiving and Network Attached Storage (NAS). The HGST Ultrastar hard drive features a robust mechanical design that exceeds the industry standard for quality and reliability. Engineered for the highest quality, the Ultrastar hard drive is put through grueling design tests during development and must pass stringent ongoing reliability testing during manufacturing.