Nike ACG Ultrafly Trail - Black/PhotonUltralight foam and enhanced grip fuel your trail speed. The Ultrafly Trail takes what you love about the original and refines it, so you can go the distance. The springy ZoomX foam is more responsive and the full length carbon plate is softer for a smooth ride. The outsole helps reduce weight while maintaining enhanced grip as the miles pile up. ZoomX foam Ultra responsive ZoomX foam midsole delivers Nike's highest energy return with a stable feel