In addition to the advanced cushioning built into the midsole, this women's running shoe also ships with an NB Response 1.0 Performance Insert to add an extra layer of comfort. 8 mm drop: due to variances created during the development and manufacturing processes, all references to 8 mm drop are approximate NB Response 2.0 performance insert No-sew material application Rubber outsole Synthetic/mesh upper Brand New Balance SKU 100232566_NP-1020490597