Be fully ready for wherever your run takes you with the Nike Shox Monster, featuring performance-enhancing construction. The Shox Monster SI features a light, mesh upper with overlays that wrap your midfoot in a snug, comfortable fit and offers great performance for runners with a neutral or underpronated gait. Four-column Nike Shox cushioning system in the heel offers cushioned support with excellent flexibility. Phylon forefoot for a smooth responsive ride. Outsole is constructed of durable BRS 1000 carbon rubber and solid rubber for long-lasting, reliable traction