26" x 22" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Grilles Measuring 4" in diameter for

Measuring 4" in diameter for the duct opening

+ Product Details Size - 18"w X 4"h is the size for the duct opening measurement only

During summer

and Diffusers

26" x 22" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Grilles Measuring 4" in diameter for+ Product Details Perfect Fit & Easy Sizing Designed for a 26" x 22" OR 22" x 26" duct opening (measured at the opening), with actual outer dimensions of 28. 5" W x 24. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 25. 75" x 21. 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