Fit Most Car Roof with Flush Side Rails. It can be easily assembled with roof luggage, luggage frame, bicycle, water sports, snowboard and other equipment. Wing shaped design, low wind resistance, low wind noise, can reduce fuel consumption. The aluminum main bar is 3.34 inch wide and 0.98 inch thick, with two internal stiffeners for greater force and a 165 lb load carrying capacity. The track clamp of the universal crossbar is adjustable in width from 33 to 47.64 inch.