The Rhino Sportz 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. The great benefit of this roof rack system is the ability to slide your crossbars along the track to accommodate various loads.The Rhino Sportz 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. The great benefit of this roof rack system is the ability to slide your crossbars along the track to accommodate various loads.