Upper Material - Smooth Leather. Slightly shiny surface, with good resistance to abrasion. Buckle - Powder coated for protection against corrosion. Attached with 4 inward curving clamps. Footbed - Original BIRKENSTOCK footbed. The famous anatomically shaped cork latex core, between two jute layers. Footbed lining - Suede leather lining 2.8 - 3 mm thick. This provides an optimum climate for your feet and unsurpassed wearing comfort. Sole unit - 10mm EVA. A great shock absorbing and lightweight material, offering exceptional grip. Adhesive - Environmentally friendly water-soluble and solvent free adhesive.