8" x 18" or 18" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 10.5" X 20.5"] Supply Grille height: 20px

height: 20px

+ Product Details Size – 16"w X 18"h is the size for the duct opening measurement only

+ Product Details Size – 18"w X 8"h is the size for the duct opening measurement only

1/4" - 6518 PSI

actual front end outer dimensions are approximately 16 5/8" width X 14 5/8" height

8" x 18" or 18" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 10.5" X 20.5"] Supply Grille height: 20px+ Product Details Perfect Fit & Easy Sizing Designed for a 8" x 18" or 18" x 8" duct opening (measured at the opening), with actual outer dimensions of 10. 5" W x 20. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 7. 75" x 17. 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