The Sierra is the perfect two-strap sandal for camping, hiking, travel, and all of your adventures. Designed with active BIRKENSTOCK fans in mind. This version pairs iconic Birkenstock features including nubuck leather uppers, classic adjustable buckle closures and suede footbed liners with direct-injection outdoor-ready outsoles for increased traction and durability. The upper is made of especially thick, oiled nubuck leather. Anatomically shaped cork-latex footbed Upper: oiled nubuck leather Sole: polyurethane (PU)