Installed over the Metal Roofing Panels under Ridge Cap or End Wall Flashing. The Roll Vent has adhesive on one side. Comes with two 10′ lengths in one box. Can be used with Classic Rib or Standing Seam systems. Very good quality. Vented Closures are approximately 2 1/2″ wide and 1 1/4″ thick prevent snow filtering but allow good air flow.