34" x 36" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 6in diameter + Product Details Size -

+ Product Details Size - 28"w X 30"h is the size for the duct opening measurement only

Constructed from sturdy 20-gauge steel

+ Product Details Size – 25"w X 36"h is the size for the duct opening measurement only

designed for optimal airflow and efficiency

actual front end outer dimensions are approximately 29

34" x 36" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 6in diameter + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 34" x 36" OR 36" x 34" duct opening (measured at the opening), with actual outer dimensions of 36. 5" W x 38. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 33. 75" x 35. 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