20" x 25" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 22.5"w X 27.5"h] w34h34 + Product Details Size –

+ Product Details Size – 12"w X 30"h is the size for the duct opening measurement only

3 * Insulation density is 30kgs/CBM = 0

With a 6" diameter for the duct opening measurement

& EN 13180 standards

20" x 25" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 22.5"w X 27.5"h] w34h34 + Product Details Size –+ Product Details Perfect Fit & Easy Sizing Designed for a 20" x 25" OR 25" x 20" duct opening (measured at the opening), with actual outer dimensions of 22. 5" W x 27. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 19. 75" x 24. 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