INNOVATIVE. The Nike Flex Run 2015 Running Shoe creates optimal airflow and a natural ride with innovative Breathe Tech construction and full length outsole flex grooves. A bootie design wraps the foot for a snug, seamless feel, and a soft, pressure mapped Phylon midsole creates superb lightweight cushioning.FEATURES Internal forefoot innersleeve construction give a secure fit, breathable lightweight midfoot support and asymmetrical design for an anatomical fit. Soft Phylon core midsole gives great cushioning right where you need it. Articulated Phylite carrier midsole provides flexible lightweight cushioning with great durability. This flexible and lightweight shoe gives you a minimal feel with cushioning to go the distance.