The Mizuno Wave Catalyst 2 continue to blend speed and support for an all-around excellent running experience. This new version features an updated midsole for better responsiveness and durability. A re-tooled upper at the forefoot provides a more comprehensive fit and breathable support.This model remains ideal for runners seeking a touch of guidance. Upper: Improve DynamotionFIT moves with the foot for secure, flexible fit. AIRmesh™ provides the utmost in breathability and comfort. Synthetic overlays deliver lightweight support. Padded tongue and heel collar enhance instep comfort. Lace-up front provides an adjustable fit. Midsole: Fan Wave provides structural guidance. New U4ic compound for the top midsole delivers optimal shock attenuation, durability and a superior ride thats 30% lighter than AP+. Wave Technology® dissipates impact forces away from the foot for a smoother, more cushioned feel on every step. Removable insole. Outsole: Blown rubber in the forefoot offers improved durability and softness. X10® durable carbon rubber delivers longer wear in high impact areas and supplements traction at heel strike. SmoothRide Engineering™ minimizes the rapid acceleration and deceleration of the foot during transition, creating the smoothest ride possible.