From On, “Made for race day. The CloudTec® cushioning system is engineered for a fast ride and combined with two layers of Helion™ HF hyper foam for energy return.” Key features Weight: 210g CloudTec® cushioning system engineered for fast runs Double layer of Helion™ HF hyper foam for energy return Carbon Speedboard® pushes you forwards, faster A lightweight, breathable mesh upper A secure fit prevents slipping, so you can focus on the race A rubber outsole delivers grip and control on curvy courses Enhanced rocker and toe-off for extra propulsion