20" x 16" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Material_Aluminum Ideal for Walls & Ceilings:

Ideal for Walls & Ceilings: Designed for seamless installation in standard 16" X 16" duct openings

+ Product Details Size – 26"w X 6"h is the size for the duct opening measurement only

width: 100%

[Outer Dimensions: 14

+ Product Details Perfect Fit & Easy Sizing - Designed for a 8" x 18" or 18" x 8" duct opening (measured at the opening)

20" x 16" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Material_Aluminum Ideal for Walls & Ceilings:+ Product Details Perfect Fit & Easy Sizing Designed for a 20" x 16" OR 16" x 20" duct opening (measured at the opening), with actual outer dimensions of 22. 5" W x 18. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 19. 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