Birki's Womens Birkis Santiago SR Flat Leather Imported Synthetic sole Birko Flor upper Classic two-strap style with fully adjustable straps for a great fit Flexible and light anatomically molded cork footbed Birko Flor is a hard-wearing material developed by Birkenstock as an alternative to leather It is made of soft acrylic and polyamide felt fibers with a durable smooth leather-like finish Flexible EVA sole provides excellent shock absorption