These are lightweight, quick-drying waraji-style sandals made by wrapping a nylon core with kimono fabric. I'm not sure about the material, but it's a smooth fabric. The heel is wool. I think a size around 25cm would be good. To wash, hand wash and put in a net for spin-drying, or if using a washing machine, put in a net and use the delicate cycle. Since there is a risk of color bleeding, please wash separately. If they feel tight or loose after wearing them for a while, try untying and retying the thong on the underside. These are handmade by an amateur, so they are not perfect. Please understand this before purchasing. Please refrain from purchasing if you have a dog allergy.