Please be advised that the Birkenstock® Narrow width can accommodate both traditional narrow and medium widths. Easy care Birko-Flor™ upper is made of acrylic and polyamide felt fibers with a leather-like texture on top and a soft fabric underneath against the skin. Slip-on silhouette with adjustable buckles at toe straps. Cork footbed is crafted from cork that is 100% renewable and sustainable. Suede-lined, contoured footbed molds to the shape of your foot for maximum comfort and support.