Nike Tri Fusion Run - Women's Treat your feet right with a combination of cushioning and support that can't be beat. Zonal sandwich mesh upper for breathability where you need it most. Dynamic webbing through the midfoot for fit and support. Dual-density midsole with large-volume, soft inner Phylon core and a firm Phylon carrier for a soft, but durable ride. Pressure-mapped outsole with flex grooves and lugs for the most traction possible. Wt. 8.5 oz.