Thule Aero Bar Underside Cover Strips connect into the slot on the underside of Thule Rapid Aero and AeroBlade load bars.  The rubber strip are cut with a sissors to fill in the gaps that the Thule foot does not occupy in the underbar slot.  Each strip is 14 inches/36 centimeters, the set of two is enough for all bar lengths and foot pack combinations.  Using the cover strips has been shown to significantly reduce load bar wind noise.  These cover strips are an excellent upgrade for the Rapid Aero load bars which do not include the strips.  The strips are also sold as a replacement for previoiusly cut strips when reconfiguring a rack system for a diffrent vehicle.