These look identical to a set of black hubs used for a wheelset on a Trek 800 mtb, about a few years old.
I came into possession of them and overhauled them and installed them on my son's new ride. They are cup/cone, not polished smooth mind you, but there weren't any pitting. A rubber cup seal like Shimano Deore/Parallax type hubs adorn the axle ends. A cheaper version may have a large 'washer' wedged onto the cone to serve as 'seal'.

They work well enough for the cash.