The soft footbed has an integrated latex foam cushion. So it offers excellent comfort from day one. 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. Cork is a sustainable material extracted from the bark layer of the cork oak. This natural product is insulating and offers very good cushioning. EVA (ethylene vinyl acetate) is a high-quality, very light, elastic material with extremely good cushioning. As a result, it smooths out slight irregularities in the floor and ensures that every step is softly cushioned.