34" x 16" Cube Core Eggcrate Return Air Filter Grille for 1" Filter sidewall For example

For example

If your hole is 14" wide by 20" tall

+ Product Details Size – 20" x 34" or 34" x 20" is the size for the duct opening measurement only

+ Product Details Size - 18"w X 18"h X 2"d (for duct opening measurement only)

actual front end outer dimensions are approximately 38 5/8" width X 32 5/8" height -

34" x 16" Cube Core Eggcrate Return Air Filter Grille for 1" Filter sidewall For example+ Product Details Perfect Fit & Easy Sizing Designed for a 34" x 16" Or 16" x 34" duct opening (measured at the opening), with actual outer dimensions of 36. 5" W x 18. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 33. 75" x 15. 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