An Air Zoom unit and soft foam offer pop and race-day speed. The Nike Zoom 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 responsive toe-off and consistent pop. Softer, More Responsive - Cushlon 3.0 foam is softer, more responsive compared to the Zoom Rival 3. Faster Transitions - Strong midfoot plastic piece offers faster, more responsive transitions compared to the previous iteration. Extra Padding - Race-inspired tongue is extra padded with perforations for comfort and breathability. Product Details - Weight - Approx. 258g/9.1oz (Men's US 10). Heel-to-toe drop - 8mm. Not intended for use as Personal Protective Equipment (PPE).