22" x 30" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Fixed Blades All of these grills have

All of these grills have dampers

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

actual front end outer dimensions are approximately 30 5/8" width X 24 5/8" height

+ Product Details Size – 36"w X 26"h is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 22" x 6" OR 6" x 22" duct opening (measured at the opening)

22" x 30" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Fixed Blades All of these grills have+ Product Details Perfect Fit & Easy Sizing Designed for a 22" x 30" OR 30" x 22" duct opening (measured at the opening), with actual outer dimensions of 24. 5" W x 30. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 21. 75" x 29. 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