Our "Aero Pads" have an inside diameter or 17/8" and are the pad to use on "factory" racks and others with the flat, wide crossbars. These crossbar pads are constructed of Sunbrella material. Sunbrella is extremely resistant to the sun's harmful rays and will not fade. Customized with our famous "Go Bananas" logo. These rack pads are sold as a pair to fit on both crossbars on the facory car/SUV rack.