USB3.0 Type A socket plastic insert
I think you might have problems finding this online simply because (as I've noticed) they tend to be mislabeled.  See Here is a board mount unit c/w shroud that is a board mount but is labeled as a panel mount.

That link may not be that handy as it has 2K minimum order quantity but it does exist.

I think that your request for the plastic part only won't work because the shroud is needed for the spring contacts to act against.  i.e. the back side of the USB mating unit needs to press against the shroud for the pins to make contact.  But then it could just be your picture not showing that.



here that part is at 3.79 a lot (100 pieces per lot)

and the mating part