Synthetic Birko-Flor upper with an adjustable strap for a custom fit Supple leather liner with Cork and latex footbed for a more shock-absorbent sandal Added arch support with deep heel cup, and raised toe bar, creating a natural walking motion for your feet The contoured footbed encourages foot health and proper posture Durable and light elastic EVA outer sole is flexible and offers great traction Please be advised that Regular accommodates Regular to Wide. Birkenstock Narrow width accommodates both traditional narrow and medium widths.