Using advanced construction techniques, this easy on / easy off shoe is more durable that others of its kind–for days spent in and around water. Features Injected EVA foam upper is more water-friendly & more durable than others of its kind External rear heel sling BLOOM performance midsole foam is made of 10% algae biomass, transforming green water into clean water in the process FloatPro Foam midsole for a lightweight ride that lasts Sizing The Hydro Moc is designed to be an easy on / easy off shoe, so sizing is generous.