28" x 26" Cube Core Eggcrate Return Air Filter Grille for 1" Filter d Actual Filter Size – 13

Actual Filter Size – 13 3/4"w x 5 3/4" x 1"

Center Core is Removable for Easy Access and Maintence

Ideal for Walls & Ceilings: Designed for seamless installation in standard 10" X 10" duct openings

Experience hassle-free installation and full adjustability for optimal airflow

28" x 26" Cube Core Eggcrate Return Air Filter Grille for 1" Filter d Actual Filter Size – 13+ Product Details Perfect Fit & Easy Sizing Designed for a 28" x 26" OR 26" x 28" duct opening (measured at the opening), with actual outer dimensions of 30. 5" W x 28. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 27. 75" x 25. 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