28" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Aluminum - Cube Core + Product Details Size –

+ Product Details Size – 25"w X 18"h is the size for the duct opening measurement only

providing efficient performance of up to 300m3/h

Filter Size - 15

The total outer size of this grille is the listed size plus 3"

Its elegant look and fine finish and the natural warmth of oak wood will change the appearance of the entire room

28" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Aluminum - Cube Core + Product Details Size –+ Product Details Perfect Fit & Easy Sizing Designed for a 28" x 18" OR 18" x 28" duct opening (measured at the opening), with actual outer dimensions of 30. 5" W x 20. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 27. 75" x 17. 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