Made for rainy-day runs, the Nike Air Zoom Structure 21 Women's Running Shoe features a water-repellent finish. The stability, support and responsive of Nike Zoom Air cushioning remains. Superb Stability A wide, flat outsole and two types of cushioning offer stability. Firmer foam cushions the arch side of the foot, while a softer foam cushions the outer side. This creates the right amount of impact protection and stability for your stride. Water-Repellent The one-piece Flymesh fabric upper has a DWR (durable, water-repellent) finish to help keep water out. It's still lightweight and breathable to help keep your feet from overheating. Breathable Protection A breathable membrane lines the inside, helping block moisture while allowing air to flow. Helping to keep your feet from overheating.