12" x 36" or 36" x 12" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Grille 75"H – fits a 16"

75"H – fits a 16" X 12" duct opening

actual front end outer dimensions are approximately 12 5/8" width X 38 5/8" height

Ideal for Walls & Ceilings: Designed for seamless installation in standard 10" X 6" duct openings

Efficient Airflow Design: The slots are meticulously angled to diversify airflow in two directions

12" x 36" or 36" x 12" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Grille 75"H – fits a 16"+ Product Details Perfect Fit & Easy Sizing Designed for a 12" x 36" or 36" x 12" duct opening (measured at the opening), with actual outer dimensions of 14. 5" W x 38. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 11. 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