30" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 6in diameter + Product Details Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 34" x 18" Or 18" x 34" duct opening (measured at the opening)

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

actual front end outer dimensions are approximately 22 5/8" width X 32 5/8" height

+ Product Details Perfect Fit & Easy Sizing - Designed for a 26" x 12" OR 12" x 26" duct opening (measured at the opening)

30" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 6in diameter + Product Details Perfect Fit+ Product Details Perfect Fit & Easy Sizing Designed for a 30" x 18" OR 18" x 30" duct opening (measured at the opening), with actual outer dimensions of 32. 5" W x 20. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 29. 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