Birkenstock MADRID women's Mules / Casual Shoes in Brown Synthetic, Available in women's sizes. 4, 7, 2, 2.5, 3, 3.5, 4.5, 5, 5.5, 7, 7.5. Upper: Birko-Flor, a very soft & durable material exclusive to Birkenstock Midsole: Cork & Latex support arch Protective edge for toes Deep heel shell Vegetable tanning (without chrome) Free Next Day Delivery & Free Returns on all orders!