18" x 24" Cube Core Eggcrate Return Air Filter Grille for 1" Filter white + Product Details Size –

+ Product Details Size – 10"w X 24"h is the size for the duct opening measurement only

+ Product Details Size - 32"w X 24"h is the size for the duct opening measurement only

+ Product Details Size – 20" x 20" is the size for the duct opening measurement only

+ Product Details Size - 16"w X 22"h is the size for the duct opening measurement only

+ Product Details Size - 36"w X 14"h is the size for the duct opening measurement only

18" x 24" Cube Core Eggcrate Return Air Filter Grille for 1" Filter white + Product Details Size –+ Product Details Perfect Fit & Easy Sizing Designed for a 18" x 24" OR 24" x 18" duct opening (measured at the opening), with actual outer dimensions of 20. 5" W x 26. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 17. 75" x 23. 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