12" x 6" or 6" x 12" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 14.5" X 8.5"] w28h28 + Product Details Size –

+ Product Details Size – 18"w X 28"h is the size for the duct opening measurement only

as the multidirectional design ensures consistent temperature control

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

+ Product Details Size - 6"w X 6"h X 2"d (for duct opening measurement only)

and brown – to harmonize with your interior theme

12" x 6" or 6" x 12" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 14.5" X 8.5"] w28h28 + Product Details Size –+ Product Details Perfect Fit & Easy Sizing Designed for a 12" x 6" or 6" x 12" duct opening (measured at the opening), with actual outer dimensions of 14. 5" W x 8. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 11. 75" x 5. 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