This is a Smog from Boohoo Woo. It's made of a material similar to a raincoat, and is for preventing stains from meals, drawing, etc. The back is open, making it easy to put on and take off. I purchased this unused item from a recycle shop, but the tag is slightly torn. There's also a transparent pocket on the front. The size is 100cm, but since it's worn over clothes, it can be used from 90cm.