FLEXIBLE, LIGHTWEIGHT COMFORT FOR ALL-DAY FUN. The Nike Sunray Adjust 5 is built to keep up with little ones in water, on land or wherever adventure takes them. The quick-dry design has a strap on top and behind the heel to keep it from slipping off. Lightweight, flexible foam provides durable cushioning that lasts. Wet to Dry Synthetic material dries quickly. Stay-in-Place Straps 2 hook-and-loop straps on top and behind the heel keep it from slipping off. The straps open all the way up to make it easy to get on and off. Comfort for Little Feet Soft, flexible foam provides lightweight, durable cushioning.