Wasps, mud dauber nests and rodents pose a serious threat to your RV vents. These and other pests can enter through vents and openings and cause serious damage by building nests that interfere with airflow in and out of your RV. Protect your valuable investment by installing Camco' s Flying Insect Screen. This easy to install screen helps ensure that your RV vents stay safe from unwanted pests. The Camco 4216 Flying Insect Screen is designed for compatibility with Norcold refrigerator vents with 6-3/16" x 17-13/16" rough opening. It is made of heavy-duty stainless steel to last through many camping seasons.