DESCRIPTION
Synology Expansion Unit DX517 5-Bay 3.5" Diskless NAS for Scalable Compatible Models (SMB) DS1517+ and DS1817+. 3 year Warranty
 
5-bay 3.5"/2.5" SATA expansion
Easily add 5 additional drive bays to Synology DiskStation1. Supporting both 2.5" and 3.5" SATA drives, DX517 is a flexible solution supporting on-the-fly volume expansion or serving as a local backup destination.
 
Hardware Applied Models:
DS1817+, DS1517+, DS918+, DS718+, DS1817, DS1517, NVR1218

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 ensures 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 easy drive installation and replacement without powering down the system. Screwless drive tray design reduces the time needed for system setup.

Dedicated local backup solution
Synology DX517 can be used as a dedicated local backup solution for the Synology DiskStation. When created as a separate volume, the DX517 provides a great backup solution to its local hard disks in case of system failure.
 
EXTERNAL LINK
- https://www.synology.com/en-us/products/DX517#specs