26" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Aluminum - Cube Core you can watch this informative

you can watch this informative video tutorial: How to Measure Your Vent Hole Before Ordering a Grille

+ Product Details Size – 14" x 22" or 22" x 14" is the size for the duct opening measurement only

actual front end outer dimensions are 13

+ Product Details Size – 14" x 28" or 28" x 14" is the size for the duct opening measurement only

26" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Aluminum - Cube Core you can watch this informative+ Product Details Perfect Fit & Easy Sizing Designed for a 26" x 18" OR 18" x 26" duct opening (measured at the opening), with actual outer dimensions of 28. 5" W x 20. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 25. 75" x 17. 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