MUJI Duvet Cover 100% Cotton, Seersucker Weave Color: Ivory 145cm x 210cm Zipper Closure With corner ties This is a cover for a summer duvet. The width is about 5cm shorter than the standard all-season size. However, it can be used without issue with a standard single size duvet because it has corner ties. I purchased two, and this one has only been used once.