18" x 10" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 6in diameter + Product Details Size –

+ Product Details Size – 28"w X 22"h is the size for the duct opening measurement only

+ Product Details Size – 14"w X 22"h is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 12" x 34" or 34" x 12" duct opening (measured at the opening)

these louvers provide exceptional protection against rain and water

Experience hassle-free installation and full adjustability for optimal airflow

18" x 10" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 6in diameter + Product Details Size –+ Product Details Perfect Fit & Easy Sizing Designed for a 18" x 10" OR 10" X 18" duct opening (measured at the opening), with actual outer dimensions of 20. 5" W x 10. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 17. 75" x 9. 75" x 1" Premium Airflow Efficiency High performance cube core eggcrate design allows 95% airflow efficiency, reducing energy costs and maximizing HVAC system lifespan. Durable, Rust Free Aluminum