16" x 10" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Adjustable Return + Product Details Size -

+ Product Details Size - 8"w X 12"h is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 30" x 20" OR 20" x 30" duct opening (measured at the opening)

+ Product Details Size - The listed 6" diameter refers specifically to the size of the duct opening

For 6" Round Duct Opening - Spiral or Flex

16" x 10" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Adjustable Return + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 16" x 10" OR 10" X 16" duct opening (measured at the opening), with actual outer dimensions of 18. 5" W x 12. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 15. 75" x 9. 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