6" x 22" or 22" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 8.5" X 24.5"] Fixed Blades with Damper + Product Details Size –

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

+ Product Details Perfect Fit & Easy Sizing - Designed for a 12" x 30" or 30" x 12" duct opening (measured at the opening)

actual front end outer dimensions are approximately 18 5/8" width X 20 5/8" height

easy unrestricted airflow

Insulation – A thick blanket of fiberglass insulation provides you with an R-Value of 4

6" x 22" or 22" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 8.5" X 24.5"] Fixed Blades with Damper + Product Details Size –+ Product Details Perfect Fit & Easy Sizing Designed for a 6" x 22" or 22" x 6" duct opening (measured at the opening), with actual outer dimensions of 8. 5" W x 24. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 5. 75" x 21. 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