8" x 16" or 16" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 10.5" X 18.5"] w20h20 + Product Details Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 14" x 6" or 6" x 14" duct opening (measured at the opening)

Actual Filter Size – 23 3/4"w x 33 3/4" x 1"

+ Product Details Size – 10" x 20" or 20" x 10" is the size for the duct opening measurement only

+ Product Details Size - 4"w X 24"h is the size for the duct opening measurement only

8" x 16" or 16" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 10.5" X 18.5"] w20h20 + Product Details Perfect Fit+ Product Details Perfect Fit & Easy Sizing Designed for a 8" x 16" or 16" x 8" duct opening (measured at the opening), with actual outer dimensions of 10. 5" W x 18. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 7. 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