6" x 20" or 20" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 8.5" X 22.5"] Powder Coated + Product Details Size -

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

+ Product Details Perfect Fit & Easy Sizing - Designed for a 14" x 30" OR 30" X 14" duct opening (measured at the opening)

actual front end outer dimensions are approximately 14 5/8" width X 28 5/8" height

+ Product Details Size – 24" x 24" with 6" collar T-Bar drop ceiling perforated return grill - metal back casing

6" x 20" or 20" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 8.5" X 22.5"] Powder Coated + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 6" x 20" or 20" x 6" duct opening (measured at the opening), with actual outer dimensions of 8. 5" W x 22. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 5. 75" x 19. 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