London Shearling Suede Leather in Color Black | BIRKENSTOCK US。Upper material: Suede Suede is a split leather with a napped finish. It has a velvety surface and is very soft to the touch. It also boasts a high moisture absorption capacity. Suede is softer and more flexible by nature and does not have the same stability as smooth leather. The stability of suede also varies from hide to hide. This does not constitute a material or production defect. Insole: Shearling Shearling is high-quality, soft sheep- or lambskin. The material is warm, breathable and has temperature-regulating properties. Footbed material: Cork Cork is a sustainable material extracted from the bark layer of the cork oak. This natural product is insulating and offers very good cushioning. Outsole: EVA 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.