The BIRKENSTOCK Madrid is the oldest member of the family of models, making it a veritable classic. Launched as a "gymnastics sandals" half a century ago, this simple single-strap model has gone on to become a firm fashion favorite. The upper is made from the skin-friendly, hard-wearing synthetic material Birko-Flor®. Tige - autres matériaux. Doublure et première de propreté - cuir. Semelle - autres matériaux.