20" x 28" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Color_Black + Product Details Size -

+ Product Details Size - 12"w X 34"h is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 26" x 8" OR 8" x 26" duct opening (measured at the opening)

preventing tampering and maintaining consistent temperature settings

+ Product Details Size - 25"w X 30"h is the size for the duct opening measurement only

+ Product Details Size – 20" x 22" or 22" x 20" is the size for the duct opening measurement only

20" x 28" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Color_Black + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 20" x 28" OR 28" x 20" duct opening (measured at the opening), with actual outer dimensions of 22. 5" W x 30. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 19. 75" x 27. 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