Synology RackStation RS422+ is a 4-bay rackmount NAS enclosed in a compact 1U chassis. Powered by the powerful Synology DiskStation Manager (DSM) operating system, it offers an affordable all-in- one solution for data sharing, synchronization, and backup to small businesses and home lab owners looking to meet their daily data management needs. Synology RS422+ is backed by Synology's 3-year limited warranty.Warranty Extension to 5 Years with the additional purchase of the EW201.