Wasps, Mud Daubers And Rodents Pose A Serious Threat To The Refrigerator On Your RV. They Can Enter Through The Refrigerator Vents And Cause Serious Damage By Building Nests That Interfere With Air Flow. Camco (Model RS700) Fits Norcold Refrigerator Vents That Have 27-1/2 Inch Long Louver Openings. These Easy To Install Screens Will Help Ensure That Your Vents Stay Free From Costly Invasion By Unwanted Pests.