Buffalo Tera Station Pro Duo dual drive NAS device with RAID capability. With RAID 1 & Hot Swap functionality, if a drive does fail, the Tera Station Pro Duo automatically powers down the faulty drive, enabling you to safely remove & replace without losing any data, or down time. The replication function allows the connection of a second Tera Station Pro Duo via the LAN port & replicates the data to improve reliability, fault tolerance or accessibility. The perfect solution for the home office or small to medium business that needs large, easy-to-deploy, easy-to-manage, redundant network attached storage.