I found this in a lot of tools that I bought secondhand

Both items were in the same baggie like you would find in an original box, so I know they go together, and they kinda fit. I assume it’s some kind of hook for a tool and/or tool belt, but lens searches only come up with tool belt hooks without the black piece, and door handles for old vehicles.

Assuming it’s a belt hook, it doesn’t seem to be a “universal” one (I don’t have a toolbelt, so no idea), so I’m trying to figure out which tool from the lot it might belong to without having to go and manually fit it to each one.