28" x 32" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Aluminum Adjustable Curved Blade + Product Details Size -

+ Product Details Size - 26"w X 4"h is the size for the duct opening measurement only

Actual Filter Size – 11 3/4"w x 25 3/4" x 1"

+ Product Details Perfect Fit & Easy Sizing - Designed for a 6" x 36" or 36" x 6" duct opening (measured at the opening)

+ Product Details Size – 18"w X 22"h is the size for the duct opening measurement only

28" x 32" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Aluminum Adjustable Curved Blade + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 28" x 32" OR 32" x 28" duct opening (measured at the opening), with actual outer dimensions of 30. 5" W x 34. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 27. 75" x 31. 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