The Thule ARB60 Aero Blade Load Bars are lightweight, strong, durable bars that are designed to greatly reduce wind noise. The AeroBlade features WindDiffuser, a textured surface on the t-slot cover that disturbs the airflow better than a smooth surface, greatly reducing wind noise. The AeroBlade also features sharp corners to promote clean "air release", helping reduce aerodynamic drag. The SwingBlade end cap pivots open to allow full access to the t-slot for easy accessory installation. SmartSide molded measurement system provides a quick, tape measure-free, no-hassle installation.