Zoot Men's Advantage 3.0-M 100% Leather and mesh Rubber sole Stability Posts - Enhancing the shoes stability and offering support for over pronators. BareFit Construction - Allowing for sockless wear and ultimate comfort. Asymmetrical Lacing System - For reduced pressure across the top ridge of the foot, and to provide an overall snug and secure fit. Z-Bound - Providing better cushioning, while keeping the weight down. CarbonSpan+ - Lighter, stronger, and faster. Tunable control that maximizes a smooth, powerful toe off for effortless forward momentum without forefoot fatigue.