12" x 30" or 30" x 12" Cube Core Eggcrate Return Air Filter Grille for 1" Filter white + Product Details Size -

+ Product Details Size - 30"w X 34"h is the size for the duct opening measurement only

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

+ Product Details Size – 30"w X 20"h is the size for the duct opening measurement only

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

12" x 30" or 30" x 12" Cube Core Eggcrate Return Air Filter Grille for 1" Filter white + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 12" x 30" or 30" x 12" duct opening (measured at the opening), with actual outer dimensions of 14. 5" W x 32. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 11. 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