This is a reversible hat purchased from Akachan Honpo. There is no size listed, but I believe it's around 47-50cm. The material feels like nylon. I used it for water play. There are no major stains, but please understand that this is a personal inspection, and there may be other overlooked stains. Please purchase with the understanding that this is a used item. Feel free to comment if you have any questions or if you'd like to purchase multiple items. Thank you.