18" x 10" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 6in diameter + Product Details Size –

+ Product Details Size – 28"w X 22"h is the size for the duct opening measurement only

1/4” - 6518 PSI

+ Product Details Perfect Fit & Easy Sizing - Designed for a 12" x 34" or 34" x 12" duct opening (measured at the opening)

Actual Filter Size – 35 3/4"w x 21 3/4" x 1"

+ Product Details Outer dimensions: 19

18" x 10" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 6in diameter + Product Details Size –+ 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