Synology DX517 5 Bay Diskless Expansion Unit

The Synology DX517 5 Bay Diskless Expansion Unit is 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 their DiskStation DS1517+ 5-Bay NAS Enclosure or DiskStation DS1817+ 8-Bay NAS Enclosure and DS1618+ ,DS918+, DS718+, DS1817 , DS1517, NVR1218. Its drive bays are hot-swappable and screwless, and included is an AC power cord, an accessory pack, and an eSATA expansion cable. With a 3 year Synology warranty.