28" x 14" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Color_White + Product Details Size -

+ Product Details Size - 36"w X 30"h is the size for the duct opening measurement only

ensuring it arrives in perfect condition

+ Product Description Upgrade your HVAC system with our 5" Round Air Vent Supply Grille

The included eight-tumbler lock and supplied key provide secure access

28" x 14" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Color_White + 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