Split bottom rack pads are easy to install on any rack. Velcro straps and elastic ties secure them to the crossbar. Dyed in yard acrylic will last many years with no fading. Aero size rack pads will work on aerodynamic style crossbars on standard racks. Typical 2.75″ x .75″. (Thule Aero Bar) (Yakima Core Bar) (Yakima Jet Stream) Sold in pairs, packaged in poly bag with header. Made in USA.