28" x 14" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Insulated Line Set 16"w X 3"h Is The

16"w X 3"h Is The Size For The Duct Opening Measurement Only

actual front end outer dimensions are approximately 30 5/8" width X 36 5/8" height

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actual front end outer dimensions are approximately 12 5/8" width X 12 5/8" height -

and Diffusers

28" x 14" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Insulated Line Set 16"w X 3"h Is The+ 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