12" x 10" or 10" x 12" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 14.5" X 12.5"] White + Product Details Size –

+ Product Details Size – 18"w X 24"h is the size for the duct opening measurement only

+ Product Details Size – 16" x 18" or 18" x 16" is the size for the duct opening measurement only

Filter Size - 13

Commercial Grade Aluminum - Will Never Rust - Designed for Warehouses

12" x 10" or 10" x 12" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 14.5" X 12.5"] White + Product Details Size –+ Product Details Perfect Fit & Easy Sizing Designed for a 12" x 10" or 10" x 12" duct opening (measured at the opening), with actual outer dimensions of 14. 5" W x 12. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 11. 75" x 9. 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