Synology Expansion Unit DX517 5-Bay 3.5" Diskless Expansion NAS ( Compatible with Selected models)

Synology DX517 offers simple storage capacity expansion solution for your DiskStation through its intuitive plug-n-use design. DX517 allows you to instantly scale up to 5 additional hard drives, so that you can expand RAID volume online or deploy the drives as a dedicated local backup destination for yourDiskstation. Models compatible - DS1819+, DS1618+, DS1019+ DS918+, DS218+, NVR1218 , DS420+,DS920+, DS720+, DS923+