6" x 8" or 8" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 8.5" X 10.5"] Copper Coil + Product Details Size -

+ Product Details Size - 8"w X 26"h is the size for the duct opening measurement only

75"H – fits a 12" X 12" duct opening

+ Product Details Size - 20"w X 22"h is the size for the duct opening measurement only

+ Product Details Size - 36"w X 12"h X 2"d (for duct opening measurement only)

6" x 8" or 8" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 8.5" X 10.5"] Copper Coil + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 6" x 8" or 8" x 6" duct opening (measured at the opening), with actual outer dimensions of 8. 5" W x 10. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 5. 75" x 7. 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