Design: Upgraded breathable engineered mesh upper Improved engineered mesh on the upper decreases weight and increases breathability Plush collar tongue and sockliner for a secure and comfortable fit MR-10 Last for a consistent fit (same as Pegasus 40) In-Shoe Comfort: ReactX foam midsole surrounds forefoot and heel Air Zoom units for an energized ride All-new ReactX foam midsole is 13% more responsive than previous React technology Durability & Traction: Signature waffle-inspired rubber outsole for traction and flexibility Additional Details: ReactX foam is engineered to reduce its carbon footprint by at least 43% in a pair of midsoles due to reduced manufacturing process energy compared to prior React foam Weight: Approx. 251 g/8.8 oz (Women's US 8) Heel-to-toe drop: 10 mm