Built to support on-the-fly volume expansion and local backups, the DX517 5-Bay Expansion Enclosure from Synology adds an additional five 3.5"/2.5" SATA drive bays to select DiskStation solutions. Its drive bays are hot-swappable and screwless, and included is an AC power cord, an accessory pack, and an eSATA expansion cable. Protection is provided by a limited 3-year warranty. General Features 5-Bay 3.5"/2.5" SATA Expansion Add five additional drive bays to your Synology DiskStation DS1817+ and DS1517+. Supporting 2.5" SATA hard drives and SSDs, as well as 3.5" SATA hard drives, the DX517 is a flexible solution supporting on-the-fly volume expansion or serving as a local backup destination. Online Volume Expansion Managed from DiskStation Manager on the host NAS, the additional bays in the DX517 are immediately ready to be used once connected. On-the-fly volume expansion helps ensure that storage and services on the host are not interrupted during volume expansion. Hot-Swappable Drive Tray Design The hot-swappable drive trays of DX517 allow drive installation and replacement without powering down the system. A screwless drive tray design also helps reduce the time needed for system setup. Dedicated Local Backup Solution Synology's DX517 can be used as a dedicated local backup solution for the Synology DiskStation DS1817+ or DS1517+. When created as a separate volume, the DX517 provides a great backup solution to its local hard disks in case of system failure. Applied Models (Supports Creating Volumes Across Different Units) 23 Series DS1823xs+, DS923+, and DS723+ 22 Series DS1522+ 21 Series DS1821+, DS1621xs+, DS1621+, and DVA3221 20 Series DS1520+, DS920+, and DS720+ 19 Series DS1819+, DS1019+, and DVA3219 18 Series DS1618+, DS918+, DS718+, and NVR1218 17 Series DS1817+, DS1817, DS1517+, and DS1517 16 Series DS916+, DS716+, and DS716+II 15 Series DS1815+, DS1515+, and DS1515