Flexible, lightweight comfort is the best way to describe the Nike Flex 2013 Run running shoe. A stretched innersleeve with breathable overlay saddle gives the best in fit and ventilation. The soft Phylonï¿½ core midsole provides great cushioning right where you need it, while an articulated Phyliteï¿½ carrier midsole adds flexible lightweight cushioning with great durability. Wt. 8.8 oz.