Nice find. I see in the reviews people are shucking these drives and putting them in NAS
I got 4 of these in the Fall for a new Rackstation I got at the same time. I put the old 4x4TB from my old 916+ in there too as a second volume. Fully stocked over here!
There is a small part of me that wants to bite the bullet and get these to build a new synology NAS....but I have everything running on a Mac Mini and backed up to google drive so I don't think its necessary.