Mizuno Women's Wave Lightning RX 100% Synthetic and mesh Rubber sole Enhanced AP midsole with increased rebound and cushion durability while maintaining lightweight performance. Shock-absorbing cushioning compound found in the forefoot. Full-length midsole ventilation system reduces heat and humidity buildup inside the shoe during performance. Triple layered mesh upper provides the utmost in breathability and comfort. Enhanced outsole rubber for improved traction and flexibility.