The Rhino-Rack Heavy Duty Cap/Topper Trackmount Roof Rack system is permanently fixed to either a pickup Cap/Topper or hard top tonneau. This system uses the Rhino-Rack Heavy Duty silver bar with tracks to complement the sleek stylish lines of your pickup 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 cross bars along the track to accommodate various sized loads.