14" x 36" or 36" x 14" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Compatible With Duct 6in engineered for seamless 360-degree airflow

engineered for seamless 360-degree airflow in T-bar ceilings

actual front end outer dimensions are approximately 18 5/8" width X 18 5/8" height

+ Product Details Size - The listed 5" diameter refers specifically to the size of the duct opening

actual front end outer dimensions are approximately 20 5/8" width X 10 5/8" height

+ Product Details Size - 12" X 12" is the size for the duct opening measurement only

14" x 36" or 36" x 14" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Compatible With Duct 6in engineered for seamless 360-degree airflow+ Product Details Perfect Fit & Easy Sizing Designed for a 14" x 36" OR 36" X 14" duct opening (measured at the opening), with actual outer dimensions of 16. 5" W x 38. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 13. 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