UPPER: Ventilated mesh. IGS (Impact Guidance System) enhances the foot's natural gait from heel strike to toe off. Propulsion Trusstic mimics the connective tissue in the foot and Space Trusstic System for foot stability. Dual Density Solyte Last for comfort. Perforated sockliner and GEL cushioning system. OUTSOLE: Durable rubber. WEIGHT: (10.3 oz.)