20" x 22" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Color_Red Oak Wood + Product Details Size –

+ Product Details Size – 18" x 34" or 34" x 18" is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 12" x 6" or 6" x 12" duct opening (measured at the opening)

+ Product Details Size - 14" X 14" is the size for the duct opening measurement only

This versatile diffuser is available in 1-way

+ Product Details Size – 8"w X 36"h is the size for the duct opening measurement only

20" x 22" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Color_Red Oak Wood + Product Details Size –+ Product Details Perfect Fit & Easy Sizing Designed for a 20" x 22" OR 22" x 20" duct opening (measured at the opening), with actual outer dimensions of 22. 5" W x 24. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 19. 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