12" x 28" or 28" x 12" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Compatible with Duct 6" + Product Details Size –

+ Product Details Size – 14" x 36" or 36" x 14" is the size for the duct opening measurement only

designed to optimize your air distribution

+ Product Details Size - 24"w X 14"h is the size for the duct opening measurement only

+ Product Details Size - 30"w X 36"h is the size for the duct opening measurement only

Actual Filter Size – 24 3/4"w x 19 3/4" x 1"

12" x 28" or 28" x 12" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Compatible with Duct 6" + Product Details Size –+ Product Details Perfect Fit & Easy Sizing Designed for a 12" x 28" or 28" x 12" duct opening (measured at the opening), with actual outer dimensions of 14. 5" W x 30. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 11. 75" x 27. 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