Expansion unit for increasing capacity of the Synology DiskStation. Synology DX517 can be combined with the following models: DS1517+ and DS1817+ - Online volume expansion - Plug and play - HotSwap hard drive bays (hard drive not included) - Hibernation mode - Managed from Synology DiskStation Manager - Includes eSATA cable for connection Synology DX517 delivers a simple solution for volume expansion and data backup for selected Synology DiskStations. The DX517 smoothly scales the storage capacity of the Synology DiskStation by an additional 5 hard drives on the fly when firmly connected directly to the Synology DiskStation, ensuring a reliable expansion solution.