Full-length carbon fiber plate increases efficiency and responsiveness. Thin rubber outsole is lightweight and grippy on the road. ZoomX foam, Nike’s lightest and most responsive foam, delivers our most energy return with every stride you take. The Zoom Fly 6 is with you every step of your run The Zoom Fly 6 is with you every step of your run. Lighter than the Zoom Fly 5, its responsive ZoomX foam adds energy return to each stride, while a carbon fiber plate helps propel you to the finish line.