28" x 12" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Aluminum Adjustable Curved Blade + Product Details Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 34" x 24" Or 24" x 34" duct opening (measured at the opening)

+ Product Details Perfect Fit & Easy Sizing - Designed for a 26" x 10" OR 10" x 26" duct opening (measured at the opening)

ensuring a perfect fit

875" width X 21

these heavy-duty louvers are ideal for use in attics

28" x 12" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Aluminum Adjustable Curved Blade + Product Details Perfect Fit+ Product Details Perfect Fit & Easy Sizing Designed for a 28" x 12" OR 12" x 28" duct opening (measured at the opening), with actual outer dimensions of 30. 5" W x 14. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 27. 75" x 11. 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