30" x 24" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 12" Diameter Adjustable airflow control - by

Adjustable airflow control - by rotating the middle disk

+ Product Details Perfect Fit & Easy Sizing - Designed for a 18" x 26" OR 26" x 18" duct opening (measured at the opening)

+ Product Details Perfect Fit & Easy Sizing - Designed for a 28" x 34" OR 34" x 28" duct opening (measured at the opening)

+ Product Details Size - 26"w X 22"h is the size for the duct opening measurement only

+ Product Details Size – 18" x 20" or 20" x 18" is the size for the duct opening measurement only

30" x 24" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 12" Diameter Adjustable airflow control - by+ Product Details Perfect Fit & Easy Sizing Designed for a 30" x 24" OR 24" x 30" duct opening (measured at the opening), with actual outer dimensions of 32. 5" W x 26. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 29. 75" x 23. 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