These are lightweight, quick-drying waraji-style sandals made by wrapping a nylon core with a smooth yukata fabric. The yukata fabric is recycled and has a smooth feel, but the exact material is unknown. Size M is recommended, suitable for feet around 23-23.5cm. To wash, hand wash and put in a net for spin-drying, or use the delicate cycle in a washing machine with a net. Wash separately as color may run. If the thong loosens or feels tight after wearing for a while, try untying and retying the thong on the underside. Please understand that these are handmade and not perfect. Please refrain from purchasing if you have a dog allergy.