18" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Color_Aluminum actual front end outer dimensions

actual front end outer dimensions are approximately 18 5/8" width X 27 5/8" height

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

875" width X 8" height

our Circular Air Supply Valves are ideal for low and medium pressure ventilation air conditioning systems

18" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Color_Aluminum actual front end outer dimensions+ 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