Leave the rest behind with the light and responsive Flex RN 2017!Predecessor: Flex 2016 RN.Support Type: Neutral to underpronation (supination).Cushioning: Lightweight, flexible response.Surface: Road.Differential: 8 mm.Circular-knit upper and lightweight synthetic overlays provide a great fit and feel. Dynamic Fit technology utilizes Flywire cables built into the lacing to promote an adaptive and supportive fit. Lace-up closure. Lightly padded tongue and collar. Breathable fabric lining offers a great in-shoe feel. Minimal, molded textile footbed. Phylon midsole features two levels of cushioning to promote a smoother ride. Auxetic tri-star outsole pattern supplies lightweight, flexible cushioning. Rounded heel encourages a natural heel strike. Rubber segments under the toe and heel deliver lasting traction and wear. Imported. Product measurements were taken using size 8.5, width B - Medium. Please note that measurements may vary by size.Weight of footwear is based on a single item, not a pair.