This belt is part of the "Hacha-Palma-Joug" triptych.
The first discoverers thought that these U-shaped objects were used as in Europe by draft animals ... non-existent on the American continent.
Many similar works have been found and most of them are engraved.
This one is completely smooth and for this reason, one can think that it is one of the oldest types, without however being sure since most of them have been discovered outside any archaeological context.
This one comes from the collection of M. A.B., Paris.