NIKE Women's Free TR Focus Flyknit Running Shoes Synthetic Imported Synthetic sole Shaft measures approximately 2.51" from arch 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.