Wasps, mud daubers, birds and rodents pose a serious threat to your RV. They can enter through the water heater vents, furnace vents, and battery vents and cause serious damage by building nests that interfere with air flow. Camco 42150 RV Flying Insect Screen - WH 200 fits Atwood furnace vents models 2540, 8516, 8520, 8525, 8531, 8535 and 8940; Suburban louvered water heater vents as well as most battery vents. This easy to install screen will help ensure that your vent stays free from costly invasion by unwanted pests.