The Rhino-Rack Vortex Cap/Topper Trackmount Roof Rack system is permanently fixed to either a pickup Cap/Topper or hard top tonneau. This system uses a pair of Rhino-Rack 54" Vortex black bars with pair of 63" tracks to complement the sleek stylish lines of your pickup while still incorporating the Rhino-Rack strength and durability. The great benefit of this roof rack system is the ability to slide your cross bars along the track to accommodate various sized loads. All Rhino-Rack Carriers and Accessories offered by The Rack Warehouse may be used with Rhino Black Vortex Aero Crossbars.