These are lightweight, quick-drying waraji-style zori (Japanese sandals) made from a smooth kimono fabric woven around a nylon core. Although made from recycled fabric, they are new as zori. The material is unknown. Recommended size is approximately 24-24.5cm. To wash, hand wash and put in a net for spin-drying, or use the delicate cycle in a washing machine with a net. Please wash separately as there is a risk of color bleeding. If the thong feels too tight or loose while wearing, try untying and retying the knot. Please understand that these are handmade and not perfect. Please refrain from purchasing if you have a dog allergy.