The Nike Rival Fly 4 can help you push your pace. Its lightweight, low-profile design has a forefoot Air Zoom unit and Cushlon 3.0 foam to help keep you fast on the road and fresh for your miles. Breathable Mesh - Lightweight mesh on upper provides breathability. Responsive Pop - A forefoot Air Zoom unit provides responsiveness at toe-off and a consistent pop. Softer, More Responsive - Cushlon 3.0 foam is softer and more responsive compared to the previous iteration. Faster Transitions - Strong, midfoot plastic piece offers faster, more responsive transitions compared to the Rival 3. Extra Padding - Race-inspired tongue is extra padded and has perforations for comfort and breathability. [] Product Details - Weight - Approx. 258 g/9.1 oz (Men's US 10). Heel-to-toe drop - 8 mm.