Brooks - Racer ST 2 (White/New Red/Thorn/Black/Silver) - Women's: A blend of lightweight speed and engineered control, the Racer ST 2 is perfect for the high performance runner who needs the added support of our Diagonal Rollbar. Optimal for tempo training and race distances from 5K to marathon. Air mesh upper provides excellent ventilation and keeps the feet cool. Synthetic suede and leather upper comfortably "wrap" the foot. 360 degrees of 3M reflectivity increases nighttime visibility. Internal thermoplastic heel counter helps stabilize the rearfoot. Molded EVA sockliner cushions the foot and enhances the fit. Full length Substance 257 midsole offers unsurpassed cushioning and durability. Hydroflow ST, optimizes cushioning and stability. Diagonal Rollbar decreases the amount and rate of pronation. DRB Accel design spans the width of the midsole increasing midfoot support. Strobel construction. Curved platform. Shoe weighs 9.0 oz.