28" x 14" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 14" Round Duct Pipe + Product Details Size –

+ Product Details Size – 22" x 32" or 32" x 22" is the size for the duct opening measurement only

+ Product Details Size - 4"w X 26"h is the size for the duct opening measurement only

the gap will expand and retract to meet perfect air supply needed

+ Product Details Perfect Fit & Easy Sizing - Designed for a 24" x 18" OR 18" x 24" duct opening (measured at the opening)

And is classified as Class 1 Fire Proof - B1

28" x 14" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 14" Round Duct Pipe + Product Details Size –+ Product Details Perfect Fit & Easy Sizing Designed for a 28" x 14" OR 14" x 28" duct opening (measured at the opening), with actual outer dimensions of 30. 5" W x 16. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 27. 75" x 13. 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