DESIGN & DETAILS: Comes with 2 Crossbars and 4 Endcaps Wind tunnel tested JetFlow(TM) teardrop shape is strong, quiet and exceptionally aerodynamic Seamless extruded aluminum construction is light, strong and sleek JetTruss(TM) internal support engineering adds serious strength for minimal weight T-slot with SmartFill(TM) push-down infill for easy mount attachment and efficient airflow Clear anodized alloy finish and high-gloss polymer end caps look awesome on your roof Streamline crossbars are compatible with any StreamLine Tower