6" x 18" or 18" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 8.5" X 20.5"] Compatible with Duct 6" + Product Details Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 10" x 12" or 12" x 10" duct opening (measured at the opening)

actual front end outer dimensions are approximately 20 5/8" width X 22 5/8" height -

+ Product Details Size - 24"w X 2"h is the size for the duct opening measurement only

Actual Filter Size – 25 3/4"w x 29 3/4" x 1"

actual front end outer dimensions are approximately 18 5/8" width X 28 5/8" height

6" x 18" or 18" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 8.5" X 20.5"] Compatible with Duct 6" + Product Details Perfect Fit+ Product Details Perfect Fit & Easy Sizing Designed for a 6" x 18" or 18" x 6" duct opening (measured at the opening), with actual outer dimensions of 8. 5" W x 20. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 5. 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 Made