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

+ Product Details Size – 8"w X 32"h is the size for the duct opening measurement only

Actual Filter Size – 7 3/4"w x 31 3/4" x 1"

+ Product Details Size - 22"w X 12"h is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 18" x 22" OR 22" x 18" duct opening (measured at the opening)

+ Product Details Size - 12"w X 32"h is the size for the duct opening measurement only

20" x 28" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Return + 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