The Birkenstock Women's Arizona Essentials EVA Sandals - Narrow are a no-fuss version of the Birkenstock cork classic. They're made from super-light and highly flexible, odor-neutral EVA (ethylene vinyl acetate) that has been tested for harmful substances. The EVA is highly elasticated, shock-absorbent, waterproof and skin-friendly to take your Birks to a whole new level of fun without the maintenance.