The New Balance W1540v2 is a lace up women's athletic running shoe with Rollbar technology for the ultimate foot stability. Due to variances created during the development and manufacturing processes, all references to 10 mm drop are approximate. Blown rubber outsole. Dual density collar foam. ACTEVA LITE 24% lighter than New Balance's standard compression molded foam for optimal compression set properties. A core of soft cushioning EVA in the midsole with a tough polyurethane rim for more support and durability. No-sew material application. Polyurethane insert. Synthetic/mesh upper.