The Rhino Aero Cap/Topper track mount roof rack system is permanently fixed to either a pick up canopy, Cap/Topper hard top tonneau or a hard resin top roof. This system uses the stylish Rhino Aero bar and track to compliment the sleek stylish lines of your vehicle while still incorporating the Rhino-Rack strength and durability. The great benefit of this roof rack system is the ability to slide your crossbars along the track to accommodate various loads.