The Gizeh brings legendary comfort and elegant detailing to the thong sandal. Birko-Flor® adds a smooth finish to the everyday favorite. Complete with classic BIRKENSTOCK design elements, like a contoured footbed that shapes to you for the ultimate in support.Birko-Flor® is a skin-friendly, tear-resistant and easy-to-care-for synthetic material which is exclusively used by BIRKENSTOCK.Natural leather can be recognized by its untreated surface. BIRKENSTOCK purposely does not treat surface grains and other characteristic features. BIRKENSTOCK uses sturdy leather with a thickness of 2.8 to 3.2 millimeters as upper material.