These boys' Nike Flex running shoes are designed with articulated, full-length flex grooves and lightweight mesh for natural and efficient range of motion plus superb breathability.SHOE TECHNOLOGIES Breathable mesh upper offers ventilation. Phylon midsole provides lightweight cushioning. Flex grooves for enhanced flexibility and a smooth, efficient stride.SHOE CONSTRUCTION Mesh/manmade upper Mesh lining Phylon midsole Rubber outsoleSHOE DETAILS Lace-up closure Padded footbed