26" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Adjustable Return + Product Details Size -

+ Product Details Size - 12"w X 12"h is the size for the duct opening measurement only

75"H – fits a 20" X 10" duct opening

Actual Filter Size – 29 3/4"w x 31 3/4" x 1"

75"H – fits a 14" X 8" duct opening

3/4" - 2981 PSI

26" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Adjustable Return + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 26" x 18" OR 18" x 26" duct opening (measured at the opening), with actual outer dimensions of 28. 5" W x 20. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 25. 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