20" x 26" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 8in diameter actual front end outer dimensions

actual front end outer dimensions are approximately 34 5/8" width X 36 5/8" height

+ Product Details Size – 36"w X 22"h is the size for the duct opening measurement only

it effectively prevents unauthorized access

+ Product Details Size – 25"w X 24"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 16 5/8" width X 18 5/8" height

20" x 26" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 8in diameter actual front end outer dimensions+ Product Details Perfect Fit & Easy Sizing Designed for a 20" x 26" OR 26" x 20" duct opening (measured at the opening), with actual outer dimensions of 22. 5" W x 28. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 19. 75" x 25. 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