6" x 26" or 26" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 8.5" X 28.5"] Aluminum Adjustable Curved Blade + Product Details Size -

+ Product Details Size - 8"w X 6"h is the size for the duct opening measurement only

+ Product Details Size – 12" x 30" or 30" x 12" is the size for the duct opening measurement only

+ Product Details Size - 25"w X 10"h is the size for the duct opening measurement only

875" width X 16" height

6" x 26" or 26" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 8.5" X 28.5"] Aluminum Adjustable Curved Blade + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 6" x 26" or 26" x 6" duct opening (measured at the opening), with actual outer dimensions of 8. 5" W x 28. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 5. 75" x 25. 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