14" x 18" or 18" x 14" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 8" Round Duct Pipe our Circular Air Supply Valves

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

High Quality – Commercial grade aluminum - will never rust - designed for warehouses

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actual front end outer dimensions are approximately 36 5/8" width X 30 5/8" height

actual front end outer dimensions are 13" Width X 13" Height

14" x 18" or 18" x 14" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 8" Round Duct Pipe our Circular Air Supply Valves+ Product Details Perfect Fit & Easy Sizing Designed for a 14" x 18" OR 18" X 14" duct opening (measured at the opening), with actual outer dimensions of 16. 5" W x 20. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 13. 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