34" x 36" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 6in diameter Ideal for Walls & Ceilings:

Ideal for Walls & Ceilings: Designed for seamless installation in standard 16" X 6" duct openings

Constructed from sturdy 20-gauge steel

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 Ideal for Walls & Ceilings:+ 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