The Brooks Asteria combines speed and support in one lightweight package so you can race with confidence. Breathable mesh upper with 3D Fit print synthetic overlays for lightweight support. BioMoGo DNA midsole adapts to every runners stride for personalized cushioning and energy return. Rearfoot Guide Rail System helps encourage a natural running stride. Midfoot Transition Zone and Segmented Crash Pad create a fast smooth transition from heelstrike to toe-off. Wt. 6.8 oz.