Synology DS3615xs 12 Bay NAS.
Upgraded to 24 GB RAM
4x Gigabit Ethernet
This can be used with two DX1215 expansion units (not included) to support up to 36 drives.
It can also house a PCIe expansion card such as 10 Gb Ethernet
For more information see here
https://global.download.synology.com/download/Document/Hardware/DataSheet/DiskStation/15-year/DS3615xs/enu/Synology_DS3615xs_Data_Sheet_enu.pdf
Fully working and tested.
Running DSM 7.1.1
*PLEASE NOTE- NO DRIVES INCLUDED*