20" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter fixed bar + Product Details Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 6" x 24" or 24" x 6" duct opening (measured at the opening)

+ Product Details Perfect Fit & Easy Sizing - Designed for a 24" x 36" OR 36" x 24" duct opening (measured at the opening)

actual front end outer dimensions are approximately 24 5/8" width X 14 5/8" height

offering maximum flexibility

Horizontal performance assures confident use of cooling temperature differential of 30 degrees Fahrenheit and greater

20" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter fixed bar + Product Details Perfect Fit+ Product Details Perfect Fit & Easy Sizing Designed for a 20" x 18" OR 18" x 20" duct opening (measured at the opening), with actual outer dimensions of 22. 5" W x 20. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 19. 75" x 17. 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