These are 100% cotton slippers from Modern Pet. These soft slippers are washable, which is one of their appealing features. They are convenient for use at home, lessons, hot springs, etc., as they can be washed (from the official website). My family seems to have bought two at the same time, so I am selling one. The website states that the inner size is approximately 26.5cm. Although unused, please consider that they have been stored at home. (No smokers, no pets) Returns are not accepted, including for reasons of size not fitting. Thank you for looking.