Nike Men's Dual Fusion Run Shield Running Shoe Breathable Mesh Upper - For breathability and a comfortable fit Dual Density Phylon Foam - With soft foam in the center and firm foam at the perimeter for plush, supportive cushioning Flex Grooves - At the midsole and outsole for enhanced flexibility and natural range of motion Inner Sleeve - For a soft, comfortable fit. Waffle Lugs - Located at the outsole for better traction.