18" x 22" or 22" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 8in diameter + Product Details Size -

+ Product Details Size - 10"w X 8"h is the size for the duct opening measurement only

you can attain the diameter of the vent

diagonally feed it through the square hole

Actual Filter Size – 19 3/4"w x 19 3/4" x 1"

actual front end outer dimensions are 32" width X 10" height

18" x 22" or 22" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 8in diameter + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 18" x 22" OR 22" x 18" duct opening (measured at the opening), with actual outer dimensions of 20. 5" W x 24. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 17. 75" x 21. 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