This is a vintage cut corner rectangular wire frame for making a tailored soft bodied lampshade. 
Base 19” x 12 1/2”
Height 12 1/2”
Top diameter 10” x 7”
Duplex fitting (for use with shade carrier which isn’t included). I would suggest an 8” carrier.
Note that this is a vintage but unused frame. It does have some scuffs etc but no flaking or rusting.