The wind noise from a roof rack may not seem like a big deal, but try listening to it for six months, or six years. Eventually it's just maddening, especially if you like to open your sunroof. The Thule AeroBlade Load Bars are specifically designed to eliminate wind noise, so you can open that sunroof back up and let the wind ruffle your flowing hair. The AeroBlade bars are made with a textured surface, like a golf ball, that disturbs airflow more than a smooth surface, to silence the wind. Thule calls it WindDiffuser. The load bars are made with BoxBeam aluminum extrusion, which can withstand a vertical load of more than 800 lbs. the AeroBars are easy to install, as well, because the Thule SmartSlide molded measurement system makes it easy to evenly place your towers. Finally, the SwingBlade end caps allow easy access to the T-Slot to make it easier to install your accessories.