Ergo Grip high-density reinforced nylon outsole: Provides stiffness and support. Velcro straps: Quick and easy fit. Synthetic leather: Easy maintenance and durability. Nylon Mesh upper: Extreme breathability and super lightness. Cleat opening under sole: Compatible with SPD cleats.Visual display for cleat's position: Accurate fit. Reflective stripe: Security and better visibility. Removable aluminum studs: Maximized grip. Ergro Grip studs: Provide a better traction off the bike under extreme conditions. Weight (size 42): 13 oz /368 g.