26" x 26" Cube Core Eggcrate Return Air Filter Grille for 1" Filter steel Actual Filter Size – 27

Actual Filter Size – 27 3/4"w x 23 3/4" x 1"

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

actual front end outer dimensions are approximately 27 5/8" width X 32 5/8" height

+ Product Details Size - 20"w X 24"h is the size for the duct opening measurement only

heat pump and centralized air ducted units

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