24" x 28" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Color_R-8.0 Pink + Product Details Size -

+ Product Details Size - 22"w X 20"h is the size for the duct opening measurement only

+ Product Details Size - 34"w X 8"h is the size for the duct opening measurement only

+ Product Details Size - 20"w X 34"h is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 12" x 18" or 18" x 12" duct opening (measured at the opening)

For 8" Round Duct Opening - Spiral or Flex

24" x 28" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Color_R-8.0 Pink + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 24" x 28" OR 28" x 24" duct opening (measured at the opening), with actual outer dimensions of 26. 5" W x 30. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 23. 75" x 27. 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