Middle-distance track racing, fast-feeling ride. Features: CloudTec® cushioning system engineered for fast runs; Helion™ HF hyper foam midsole for responsiveness; A nylon-blend Speedboard® for propulsive push-offs; Light, breathable one-piece upper; Six spikes and strategically placed grip; Secure upper construction that locks your foot in; Race legal. Materials: Recycled Polyester. Built in close collaboration with elite track runners, for middle-distance track performance. Crafted using advanced engineering and data-driven geometry enhancements, these spikes feature an optimized stack height, up to the 20mm limit – unlocking the full potential, within race-day regulations.. Harnessing our CloudTec® cushioning system engineered for your fastest runs. A nylon-blend Speedboard® evenly distributes force and amplifies responsiveness, for powerful push-offs. While the Helion™ HF hyper foam midsole delivers responsiveness with each stride.