Speed and support collide in the Mizuno Wave Catalyst 2. AIRmesh upper for a breathable, lightweight fit and feel. DynamotionFit construction conforms to the foot for a snug, secure fit that moves with you. Pebax Fan Wave encourages a smooth transition from heelstrike to toe-off. U4icX midsole foam cushions impact and creates a smooth running stride. Full-length rubber outsole for durable traction on any surface. Wt. 9.5 oz.