Vintage Mid-Century Industrial Utility Light
 
This light would have been a flush mount, most likely produced between the 1940s and 1960s. It has antiquated wiring, which will need replacing/updating if you are planning to use it. The metal rim is discolored due to age, and rust is present on the fixture. The glass dome is ribbed. The base pan is 12" and the light as a whole is about 5.5" from the base to the bottom of the lamp. This particular style of lighting would have been common in schools, industrial spaces, and/or municipal buildings. Exact manufacturer is unknown. Sold as is.