What's the background with all the 'Dell G14' branded HDDs on serverpartsdeals?

I'm looking at 12TB HDDs, and there are dozens of "Dell G14 ... 7.2K RPM SATA 6Gb/s 512e 3.5in Refurbished HDD" drives, all with very slightly different model numbers, all for around $14.50/TB.

I can't find much about them on Google or this sub, like who makes them, datasheet, how reliable they might be, etc.

"PMR" I'm guessing is a disk format strategy like CMR/SMR, maybe older?

"Ships in a Dell G14 tray" - are they keyed to only work with Dell servers, or they're actually just regular, standards-compliant SATA?

Who makes them before they get a Dell logo? Are they to be avoided?

(Goal: I'm looking for a single large drive to hold lots of easily replaced write-once/read-many files like linux ISOs)