18" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 6" Round Duct Pipe See our separate listing for

See our separate listing for T-Bar supply grille

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

+ Product Details Size – 20" x 24" or 24" x 20" is the size for the duct opening measurement only

+ Product Details Size - 32"w X 14"h is the size for the duct opening measurement only

Actual Filter Size – 24 3/4"w x 9 3/4" x 1"

18" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 6" Round Duct Pipe See our separate listing for+ Product Details Perfect Fit & Easy Sizing Designed for a 18" x 8" OR 8" X 18" duct opening (measured at the opening), with actual outer dimensions of 20. 5" W x 10. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 17. 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