20" x 34" or 34" x 20" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Insulated Line + Product Details Size -

+ Product Details Size - 16"w X 16"h is the size for the duct opening measurement only

+ Product Details Size – 36"w X 34"h is the size for the duct opening measurement only

6" width X 9

+ Product Details Size – 26"w X 20"h is the size for the duct opening measurement only

Actual Front End Outer Dimensions Are 3

20" x 34" or 34" x 20" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Insulated Line + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 20" x 34" OR 34" x 20" duct opening (measured at the opening), with actual outer dimensions of 22. 5" W x 36. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 19. 75" x 33. 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