The Birkenstock Men’s Women’s Madrid Birko-Flor Sandals have a single-strap and the upper is made from the skin-friendly, hard-wearing synthetic material Birko-Flor. The cork footbed is anatomically shaped and there is a suede footbed lining. The deep heel cup provides support for the foot and the EVA outsole offers stability. The interior and exterior longitudinal arch supports help to keep the foot in place and the transverse arch support helps to keep the foot straight. The toe grip helps to keep the toes in place and the footbed edge protects the toes.