30" x 30" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Compatible With Duct 12in + Product Details Size -

+ Product Details Size - 26"w X 20"h is the size for the duct opening measurement only

and keep the cold air out during the Winter Months

+ Product Details Size - 20"w X 8"h is the size for the duct opening measurement only

This simple adjustment reduces HVAC strain

30" x 30" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Compatible With Duct 12in + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 30" x 30" duct opening (measured at the opening), with actual outer dimensions of 32. 5" W x 32. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 29. 75" x 29. 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 from