18" x 32" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 6" Diameter + Product Details Size –

+ Product Details Size – 36"w X 30"h is the size for the duct opening measurement only

+ Product Details Size – 30"w X 8"h is the size for the duct opening measurement only

75"H – fits a 16" X 4" duct opening

Actual Filter Size – 9 3/4"w x 25 3/4" x 1"

+ Product Details Size – 32"w X 25"h is the size for the duct opening measurement only

18" x 32" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 6" Diameter + Product Details Size –+ Product Details Perfect Fit & Easy Sizing Designed for a 18" x 32" OR 32" x 18" duct opening (measured at the opening), with actual outer dimensions of 20. 5" W x 34. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 17. 75" x 31. 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