A waterproof alternative to the Classic Birkenstock Gizeh. Great for the beach or beside the pool. This style must not be left in direct sunlight and is not designed to be worn day in day out, for long periods of time or on lengthy walks. This EVA style is manufactured in the Regular width only. EVA - Ethyl Vinyl Acetate - is a non-toxic synthetic compound. It creates lightweight and flexible footwear that is shock absorbent. Also resistant to water, oil, and grease. It can shrink at high temperatures. This footbed is lightweight and flexible and still offers contours and arch support.