This is a neat vintage Clear Glass light bulb cover shade part that has a etched pattern design for a decorative look to this shade cover. It would be for some type of a  Hanging light fixture that it would go over a bulb and tighten up with set screws to hold it on the fixture and cover light bulb is my best idea for what it would go to i think. Its in good shape with a small chip on the top outer rim part and i seen a small little crack on the shade also but its very small and this part is in good condition and can be used still so its a fine vintage lighting cover part. This item measures 4 3/4" x 4 3/4" x 4" tall and the diameter of the top is 2 1/4" and the inner area is 1 1/2" in diameter to give you an idea of what it might fit into and slide over for the bulb that it would cover.