28" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Aluminum Bar With these options

With these options

+ Product Details Size - 20"w X 8"h is the size for the duct opening measurement only

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+ Product Details Size – 12" x 32" or 32" x 12" is the size for the duct opening measurement only

listed size +2" diameter

28" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Aluminum Bar With these options+ Product Details Perfect Fit & Easy Sizing Designed for a 28" x 8" OR 8" x 28" duct opening (measured at the opening), with actual outer dimensions of 30. 5" W x 10. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 27. 75" x 5. 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