20" x 14" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Compatible with Duct 8" it effectively prevents unauthorized access

it effectively prevents unauthorized access

With a 6" diameter for the duct opening measurement

+ Product Details Size – 26"w X 22"h is the size for the duct opening measurement only

and matte black

+ Product Details Perfect Fit & Easy Sizing - Designed for a 28" x 20" OR 20" x 28" duct opening (measured at the opening)

20" x 14" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Compatible with Duct 8" it effectively prevents unauthorized access+ Product Details Perfect Fit & Easy Sizing Designed for a 20" x 14" OR 14" x 20" duct opening (measured at the opening), with actual outer dimensions of 22. 5" W x 16. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 19. 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