Ventamatic 18 In. Automatic Metal Shutter for Gable Mount Power Attic Ventilators XXMPNOZZLE This unit is fully assembled VX2414AABL This unit is fully assembled and ready to work—transport it anywhere using the on board handles with cord wrap and 9 in Minimal assembly with no tools is required to get started just screw on the cradle base with the provided knobs and you're ready to go Add our automatic shutter to finish your install of Standard and Premium series Cool Attic Ventamatic Gable Mount Ventilators if you are not installing behind existing louvers This shutter unit automatically opens and closes when the fan turns on and off and helps to shield your attic space from the elements when the fan is not in use