28" x 36" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 10" Diameter + Product Description Maximize the

+ Product Description Maximize the efficiency of your ventilation system with our top-of-the-line HVAC grilles and registers

Actual Filter Size – 31 3/4"w x 23 3/4" x 1"

+ Product Details Size – 20" x 28" or 28" x 20" is the size for the duct opening measurement only

Actual Filter Size – 29 3/4"w x 15 3/4" x 1"

Tailored for Your Needs: Specifically suited for 24x24 lay-in diffusers

28" x 36" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 10" Diameter + Product Description Maximize the+ Product Details Perfect Fit & Easy Sizing Designed for a 28" x 36" OR 36" x 28" duct opening (measured at the opening), with actual outer dimensions of 30. 5" W x 38. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 27. 75" x 35. 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