22" x 26" or 26" x 22" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w18h18 + Product Details Size –

+ Product Details Size – 24"w X 28"h is the size for the duct opening measurement only

For example

Say goodbye to pest-related worries as the built-in back 1/2" mesh acts as a barrier against unwanted rodents like mice

+ Product Details Size – 18"w X 36"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 20 5/8" width X 10 5/8" height

22" x 26" or 26" x 22" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w18h18 + Product Details Size –+ Product Details Perfect Fit & Easy Sizing Designed for a 22" x 26" OR 26" x 22" duct opening (measured at the opening), with actual outer dimensions of 24. 5" W x 28. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 21. 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