The Sibyl sandal from Papillo is a strappy wedge-heel sandal featuring narrow straps and elegant ring buckles. The upper is made from extra thick, oiled nubuck leather. Upper: oiled nubuck leather Footbed lining: suede Sole: light polyurethane sole (PU) Heel type: wedge heel, heel height: 40 mm Details: ankle strap with an individually adjustable metal pin buckle Made in Portugal Upper material: Oiled leather Oiled leather is one of our favourite types of leather. Its oily waxed surface makes for a unique colour effect and develops a beautiful patina. The oily finish of our natural leather products results in colour variation, making each and every pair unique. Insole: Natural leather Natural 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. Footbed material: Polyurethane Polyurtehane (PU) is a flexible, water- and dirt-repellent synthetic material which makes footwear easy to care for.