18" x 10" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Color_Anodized Aluminum + Product Details Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 20" x 6" OR 6" x 20" duct opening (measured at the opening)

Universal size

+ Product Details Perfect Fit & Easy Sizing - Designed for a 6" x 34" or 34" x 6" duct opening (measured at the opening)

+ Product Spec Sheet Floor Register Spec Sheet

Actual Filter Size – 29 3/4"w x 23 3/4" x 1"

18" x 10" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Color_Anodized Aluminum + Product Details Perfect Fit+ Product Details Perfect Fit & Easy Sizing Designed for a 18" x 10" OR 10" X 18" duct opening (measured at the opening), with actual outer dimensions of 20. 5" W x 10. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 17. 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