3rd tier binned drives at best. Used at worse. They're a division of GoHardDrive.
Q: Is it true that the drives in externals can be: overstock, overruns, binned (out of spec drives), from cancelled orders.
A: Yes to all of it. Externals are the lowest bins above the [redated] (Edit: binned rives} we sell to third parties. It’s whatever is leftover. They have less warranty because they aren’t expected to last as long.
My notes: The first part is supported by what I posted in this thread, https://www.reddit.com/r/DataHoarder/comments/11jmot5/to_those_asking_what_drive_is_inside_my_wd/ which has a link to WD's disclosure about this.
It's been confirmed by another source that the binned drives, are drives that are Out Of Spec, flashed with special firmware that can't be updated and is no longer supported by the manufacturer. This is source of SOME of the unbranded drives from certain resellers.
https://www.reddit.com/r/DataHoarder/comments/146hb9k/information_about_cmr_to_smr_manufacturer/
https://www.reddit.com/r/DataHoarder/comments/15oihst/anyone_ever_shucked_an_avolution_drive/
https://www.goharddrive.com/Avolusion-1TB-USB-3-0-External-PS4-Gaming-HDD-p/g03-1485-ps.htm