16" x 16" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum 18in diameter while its modern design complements

while its modern design complements any space

Its elegant look and fine finish and the natural warmth of oak wood

+ Product Details Size - 36"w X 20"h is the size for the duct opening measurement only

Actual Filter Size – 17 3/4"w x 17 3/4" x 1"

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

16" x 16" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum 18in diameter while its modern design complements+ Product Details Perfect Fit & Easy Sizing Designed for a 16" x 16" duct opening (measured at the opening), with actual outer dimensions of 18. 5" W x 18. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 15. 75" x 15. 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 Made from