6" x 20" or 20" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 8.5" X 22.5"] 18in diameter margin-right: 8px

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+ Product Details Size - 6"w X 28"h is the size for the duct opening measurement only

3/8" - 4223 PSI

[Outer Dimensions: 10

6" x 20" or 20" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 8.5" X 22.5"] 18in diameter margin-right: 8px+ Product Details Perfect Fit & Easy Sizing Designed for a 6" x 20" or 20" x 6" duct opening (measured at the opening), with actual outer dimensions of 8. 5" W x 22. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 5. 75" x 19. 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 Made