Wasps, mud daubers and rodents pose a serious threat to the refrigerator vents on your RV. They can enter through the refrigerator vents and cause serious damage by building nests that interfere with air flow. Camco (model RS 500) flying insect RV refrigerator screen fits Norcold refrigerator vents which have 19-3/4 Inch long louver openings. These easy to install screens will help ensure that your vents stay free from costly invasion by unwanted pests.