mod vintage frameless mirror circle, art deco or mid-century modern big round dot!
more photos of this product belowFrameless beveled glass mirror backed with heavy hardboard masonite, with a sturdy wire for hanging. This might be anywhere in age from 1930s to 1960s, classically deco moderne style.
It's about 24"" in diameter, in very good condition overall. The silvering is not flawless, but quite nice for a piece of its age. Edges look good.