36" x 14" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Brown + Product Details Size -

+ Product Details Size - 20"w X 25"h is the size for the duct opening measurement only

These are specially sized to fit into all drop ceilings

+ Product Details Perfect Fit & Easy Sizing - Designed for a 16" x 28" OR 28" X 16" duct opening (measured at the opening)

please note that the total outer dimensions of the grille measure 7" in diameter

+ Product Details Perfect Fit & Easy Sizing - Designed for a 22" x 28" OR 28" x 22" duct opening (measured at the opening)

36" x 14" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Brown + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 36" x 14" OR 14" x 36" duct opening (measured at the opening), with actual outer dimensions of 38. 5" W x 16. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 35. 75" x 13. 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