30" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w20h20 + Product Details Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 10" x 24" or 24" x 10" duct opening (measured at the opening)

+ Product Details Size - 4"w X 26"h is the size for the duct opening measurement only

Traditional HVAC systems were designed for cold air

12"w X 3"h Is The Size For The Duct Opening Measurement Only

30" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w20h20 + Product Details Perfect Fit+ Product Details Perfect Fit & Easy Sizing Designed for a 30" x 8" OR 8" x 30" duct opening (measured at the opening), with actual outer dimensions of 32. 5" W x 10. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 29. 75" x 7. 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