Breathable mesh upper with synthetic overlays for a snug, supportive fit. Forefoot GEL Cushioning System absorbs shock with every step. SpEVA midsole for cushioning and bounce back. Full-length Guidance Line vertical flex groove improves your running gait. ASICS High Abrasion Rubber in the heel for durable traction. DuraSponge in the forefoot for enahnced flexibility. Wt. 9.5 oz.