The often imitated, never duplicated, category-defining, two-strap wonder from Birkenstock. A comfort legend and a fashion staple. With adjustable straps and a magical cork footbed that conforms to the shape of your foot, a truly custom fit is as effortless as the classic design. With its additional foam layer, the soft footbed offers extra comfort and pampers feet – all day long. Oiled 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.