Camco RV Flying Insect Screen for Dometic 6-Gallon Water Heaters (WH-6GEA) Wasps, Mud Daubers and Rodents Pose a Serious Threat to your RVs Water Heater. They Can Enter Through the Vent and Cause Serious Damage by Building Nests That Interfere with Air Flow. This Flying Insect Screen Fits Dometic WH-6GEA 6-gallon Water Heater Vents. The Screen Measures 3 ½-inches (L) x 3 5/16-inches (W) x 1/16-inch (thick). It is Easy to Install and will Help Ensure That Your Vent Stays Free From Costly Invasion by Unwanted Pests.