28" x 22" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 18" Diameter + Product Details Size -

+ Product Details Size - 20"w X 30"h is the size for the duct opening measurement only

+ Product Details Size - 25"w X 14"h is the size for the duct opening measurement only

+ Product Details Size – 16"w X 22"h is the size for the duct opening measurement only

+ Product Details Size – 16" x 24" or 24" x 16" is the size for the duct opening measurement only

28" x 22" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 18" Diameter + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 28" x 22" OR 22" x 28" duct opening (measured at the opening), with actual outer dimensions of 30. 5" W x 24. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 27. 75" x 21. 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