Tube Style pads are sewn closed at the bottom. For installation they slide onto the crossbar from an open end. Dyed in yard acrylic will last many years with no fading. For 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.