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 that we are renowned for. The great benefit of this roof rack system is the ability to slide your crossbars along the track to accommodate various loads.