A layer of Helion HF for max energy return and rebound; Propulsive nylon-blend Speedboard; Engineered woven mesh upper that's breathable and ultralight; Reflective elements help you shine; Rockered geometry for a fast, forward-rolling ride; Updated toebox design for fast training sessions; Forefoot grip for added support during the toe-off phase; Design inspired by On's pinnacle, race-winning super shoes; Heel to Toe Drop: 8mm; Weight: 281 g / 9.9 oz