These are waraji-style sandals made with a soccer cloth yukata and a nylon core. They are made of cotton, but are slightly weaker than regular fabric. They are made from recycled yukata fabric, but are new as sandals. Size is M, approximately 23-23.5cm. To wash, hand wash and put in a net to spin dry, or if using a washing machine, put in a net and wash on the delicate cycle. If they become too tight or loose after wearing them for a while, untie and retie the thong on the underside. These are handmade, so they are not perfect. Please understand this before purchasing. Please refrain from purchasing if you have a dog allergy.