30" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 8" Diameter actual front end outer dimensions

actual front end outer dimensions are approximately 18 5/8" width X 30 5/8" height

5" - SEE BELOW IN DESCRIPTION How To Measure A Grille

+ Product Details Size - 24"w X 36"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 36 5/8" width X 18 5/8" height

30" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 8" Diameter actual front end outer dimensions+ Product Details Perfect Fit & Easy Sizing Designed for a 30" x 8" OR 8" x 30" duct opening (measured at the opening), with actual outer dimensions of 32. 5" W x 10. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 29. 75" x 7. 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