20" x 34" or 34" x 20" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Fixed Blades with Damper + Product Details Size -

+ Product Details Size - The listed 10" diameter refers specifically to the size of the duct opening

+ Product Details Size – 12"w X 12"h

+ Product Details Perfect Fit & Easy Sizing - Designed for a 30" x 30" duct opening (measured at the opening)

making it a reliable choice for improving indoor air quality

20" x 34" or 34" x 20" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Fixed Blades with Damper + 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