We paired Nike ReactX foam with two Air Zoom units (one in the forefoot and one in the heel) to give you a bouncy, springy sensation and an energized feel at toe-off. Signature waffle-inspired rubber outsole provides traction and flexibility. Plush collar, tongue and soft sockliner for a secure and comfortable fit Engineered mesh upper is lighter and more breathable than the Pegasus 40. Responsive cushioning in the Pegasus provides an energized ride for everyday road running. Experience lighter-weight energy return with dual Air Zoom units and a ReactX foam midsole. Improved engineered mesh on the upper decreases weight and increases breathability.