Nike Men's Air Zoom Structure 19 Flash Running Shoes From the Flymesh upper to the triple-density foam midsole, the Nike Air Zoom Structure 19 Flash Men's Running Shoe offers plenty of support and the response you need for fast-paced runs. A reflective, water-repellent upper keeps you visible, dry and comfortable in dark, dreary conditions Full, mesh inner sleeve for breathability and a sock-like fit Internal heel counter for a snug, secure fit Waffle outsole provides durability and multi-surface traction Lateral outsole crash rail encourages soft, smooth transitions Deep flex grooves for more natural movement