28" x 28" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 14in diameter + Product Details Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 18" x 32" OR 32" x 18" duct opening (measured at the opening)

actual front end outer dimensions are approximately 16 5/8" width X 38 5/8" height

16" x 3" Aluminum Spiral Duct Air Vent Grille Cover - Fully Adjustable Double Deflection HVAC Air Supply

with actual outer dimensions of 10

+ Product Details Size - 20"w X 24"h is the size for the duct opening measurement only

28" x 28" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 14in diameter + Product Details Perfect Fit+ Product Details Perfect Fit & Easy Sizing Designed for a 28" x 28" duct opening (measured at the opening), with actual outer dimensions of 30. 5" W x 30. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 29. 75" x 29. 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 from