Vintage Atomic MCM Glass Ceiling Square Light Fixture Cover 50's Era White

vintage atomic mcm glass ceiling square light fixture cover 50's era white. Measures approximately 5 3/4 inches x 5 3/4 inches. It is about 4 inches tall and the inside rim where it mounts is 5 1/2 inches across. The fixture has a clear bottom and white on the sides with an atomic design. This square light cover with rounded corners and a ribbed 'dental' design around one edge is in excellent vintage shape. There are no visible cracks or chips. There are a couple pencil tip size marks where the rim would touch the mount, but they would not show when mounted.