20" x 20" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Filter Grille while the ingenious dial-controlled damper

while the ingenious dial-controlled damper empowers you to effortlessly regulate airflow using your foot

+ Product Details Size – 6" x 24" or 24" x 6" is the size for the duct opening measurement only

+ Product Details Size - 26"w X 24"h is the size for the duct opening measurement only

Its linear bar design maximizes ventilation

with actual outer dimensions of 12

20" x 20" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Filter Grille while the ingenious dial-controlled damper+ Product Details Perfect Fit & Easy Sizing Designed for a 20" x 20" duct opening (measured at the opening), with actual outer dimensions of 22. 5" W x 22. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 19. 75" x 19. 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