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"] Color_Red Oak 75"H – fits a 14"

75"H – fits a 14" X 6" duct opening

+ Product Details Size - 25"w X 36"h is the size for the duct opening measurement only

Actual Filter Size – 21 3/4"w x 5 3/4" x 1"

12"w X 2"h Is The Size For The Duct Opening Measurement Only

+ Product Details Size - The listed 12" diameter refers specifically to the size of the duct opening

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"] Color_Red Oak 75"H – fits a 14"+ 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