This New Balance running shoe for women has a NB Response 1.0 performance insert for superior comfort. 8 mm drop: due to variances created during the development and manufacturing processes, all references to 8 mm drop are approximate. Engineered mesh. Fresh Foam innovative midsole created from a single piece of foam that provides a plush, more natural ride. NB Response 1.0 performance insert. No sew overlays in optimal areas. Rubber outsole. Synthetic/mesh upper.