28" x 12" Cube Core Eggcrate Return Air Filter Grille for 1" Filter rg1010 + Product Details Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 8" x 12" or 12" x 8" duct opening (measured at the opening)

Achieve the perfect airflow with adjustable control by rotating the middle disk

Actual Filter Size – 15 3/4"w x 21 3/4" x 1"

actual front end outer dimensions are approximately 14 5/8" width X 20 5/8" height -

Equipped with a locking eight-tumbler key system

28" x 12" Cube Core Eggcrate Return Air Filter Grille for 1" Filter rg1010 + Product Details Perfect Fit+ Product Details Perfect Fit & Easy Sizing Designed for a 28" x 12" OR 12" x 28" duct opening (measured at the opening), with actual outer dimensions of 30. 5" W x 14. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 27. 75" x 11. 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