Protects your RV's interior from rain damage while allowing your roof vent to remain open. Allows constant airflow through your RV to stop heat build-up. Musty air, heat, smoke, and cooking odors escape while rain stays out. Features MaxxAir's exclusive Zero-Leak Mounting System that eliminates the need to drill any holes in your RV's roof surface. Mounts to most popular 14" x 14" standard roof vents. Three year limited warranty. 19.5" long x 18.5" wide x 9" tall.