Birkenstock Men's Work Clog Profi-Birki Black is made of 100% Alpro-Foam. Made in Germany.Upper Polyurethane, also known as PU, is a synthetic material ideally suited for use outdoors. The material is water-repellent and dirt-resistant and extremely easy to care for. Birkenstock Men, Shoe Size Conversion, Synthetic Materials, Us Man, Womens Size Chart, Womens Clogs, Repellent, Birkenstock, Water Repellent