32" x 24" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Width_20in + Product Details Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 24" x 22" OR 22" x 24" duct opening (measured at the opening)

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

40" x 16" Aluminum Spiral Duct Air Vent Grille Cover - Fully Adjustable Double Deflection HVAC Air Supply

+ Product Details Size - 18"w X 4"h is the size for the duct opening measurement only

these heavy-duty louvers are ideal for use in attics

32" x 24" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Width_20in + Product Details Perfect Fit+ Product Details Perfect Fit & Easy Sizing Designed for a 32" x 24" OR 24" x 32" duct opening (measured at the opening), with actual outer dimensions of 34. 5" W x 26. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 31. 75" x 23. 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