16" x 32" or 32" x 16" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Compatible with Duct 8" + How To Measure A

+ How To Measure A Round Vent Overall Size:

+ Product Details Size – 28"w X 28"h is the size for the duct opening measurement only

For 6" Round Duct Opening - Spiral or Flex

each diffuser is carefully shrink-wrapped with a sturdy cardboard backing

16" x 32" or 32" x 16" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Compatible with Duct 8" + How To Measure A+ Product Details Perfect Fit & Easy Sizing Designed for a 16" x 32" OR 32" X 16" duct opening (measured at the opening), with actual outer dimensions of 18. 5" W x 34. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 15. 75" x 31. 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