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 Merrell is focused on merging performance, styling, and comfort to empower all people to confidently explore the outdoors Merrell Air Cushion in the heel absorbs shock and adds stability