A classic to wear all year long: the Birkenstock Boston Soft Footbed Clog. Suede or leather upper in a comfort clog style with a round toe Slip-on entry Adjustable buckle accent Original BIRKENSTOCK soft, anatomically-shaped footbed Durable EVA outsole Birkenstock is committed to environmentally friendly operations. A high proportion of the natural materials that we use are from sustainable sources: cork, natural latex, jute, leather, wool felt, copper and brass are among our most important materials.