Received these as a gift and have only worn around the house once to try them on. The store description of the sandal is below. The BIRKENSTOCK Florida is the ideal sandal for anyone who spends a lot of time on their feet and sets great store by comfort above and beyond the norm. The anatomically formed original BIRKENSTOCK cork-latex soft footbed with built-in permanently elastic latex cushion ensures outstanding comfort that starts on day one. The upper is made of skin-friendly, hard-wearing Birko-Flor®. Anatomically shaped cork-latex soft footbed with integrated permanently elastic latex cushion Upper: Birko-Flor® Lining: suede Sole: EVA Details: strap with three individually adjustable metal pin buckles