18" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter d With a 6" diameter for

With a 6" diameter for the duct opening measurement

+ Product Details Size - 6"w X 28"h is the size for the duct opening measurement only

+ Product Details Size – 25"w X 20"h is the size for the duct opening measurement only

+ Product Description Upgrade your HVAC system with a high-quality aluminum return grille designed for a clean

18" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter d With a 6" diameter for+ Product Details Perfect Fit & Easy Sizing Designed for a 18" x 6" OR 6" X 18" duct opening (measured at the opening), with actual outer dimensions of 20. 5" W x 8. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 17. 75" x 5. 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