New, never worn except to try on in house! Size 41 (women's 10-10.5, men 8-8.5) black Birkenstock Medina Birko-Flor sandals. I love these, but they are one size too big for me. Upper material: Birko-Flor* Birko-Flor® is a skin-friendly, tear-resistant and easy-to-care-for synthetic material which is exclusively used by BIRKENSTOCK.