12" x 32" or 32" x 12" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Outdoor Vent Covers this grille offers durability and

this grille offers durability and resistance to rust and corrosion

+ Product Details Perfect Fit & Easy Sizing - Designed for a 14" x 28" OR 28" X 14" duct opening (measured at the opening)

+ Product Details Size - 20"w X 18"h is the size for the duct opening measurement only

Actual Filter Size – 29 3/4"w x 29 3/4" x 1"

+ Product Details Perfect Fit & Easy Sizing - Designed for a 8" x 12" or 12" x 8" duct opening (measured at the opening)

12" x 32" or 32" x 12" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Outdoor Vent Covers this grille offers durability and+ Product Details Perfect Fit & Easy Sizing Designed for a 12" x 32" or 32" x 12" duct opening (measured at the opening), with actual outer dimensions of 14. 5" W x 34. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 11. 75" x 31. 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