This is a small round ceiling light or lampshade made from ribbed opaque white glass decorated with a spider design in black metal across the top and probably dating from the 1950s or 1960s. Approximate dimensions are 27cm (10.5") in overall diameter across the widest part and 18.5cm (7.25") in height excluding the fitting.
The lampshade is in good overall condition with no damage but does have some general signs of cosmetic wear. There are a few surface marks to the glass shade and some wear to the finish and general tarnishing of the metal parts.