From Nike, the Girls' Flex Runner 4 PS Running Sneakers feature:  Mesh upper Pull tabs on the heel and tongue work with a stretchy inner sleeve to help make these shoes easy for kids to put on themselves Elastic straps run behind the heel and across the top of the foot to provide a snug, secure feel Slip-on construction Fabric lining Soft, springy foam in the midsole helps cushion their every step Flex grooves in the outsole add flexibility, helping every step feel natural Rubber outsole Imported.