14" x 28" or 28" x 14" Cube Core Eggcrate Return Air Filter Grille for 1" Filter return grille + Product Details Size –

+ Product Details Size – 24"w X 36"h is the size for the duct opening measurement only

+ Product Details Size – 30"w X 10"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 14 5/8" width X 38 5/8" height -

+ Product Details Size - 20"w X 12"h is the size for the duct opening measurement only

back blades made of black plastic for reduced air noise and discreet appearance

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