Clock glass that came from clock collectors collection. I think I have 50 of these. New old stock Standard Electric Time glass for wall clocks. 12.25 inches width, depth 1/16 inches. Edges might have extremely tiny flea bite nicks. Glass is flat and not convex as it should be. Photo with Nickel and quarter next to it for depth perception. Glass is slightly thicker than a nickel. Real glass not that thin trash.