Built for movement, the Nike Men's Flex RN has flex grooves on the outsole that help promote natural movement. A versatile design delivers comfort your entire run. DESIGN: Stretchy material at the toe helps you move freely during your run IN-SHOE COMFORT: Deconstructed heel conforms to your foot, helping you feel secure Support at the midfoot adds a snug, comfortable fit TRACTION & DURABILITY: Full-length rubber outsole keeping things moving with durable traction