30" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Copper Coil-Insulated Line Set + Product Details Size -

+ Product Details Size - 20"w X 36"h is the size for the duct opening measurement only

+ Product Details Size – 14"w X 12"h is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 16" x 12" OR 12" X 16" duct opening (measured at the opening)

+ Product Details Size – 12"w X 4"h is the size for the duct opening measurement only

+ Product Details Size - 30"w X 4"h is the size for the duct opening measurement only

30" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Copper Coil-Insulated Line Set + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 30" x 8" OR 8" x 30" duct opening (measured at the opening), with actual outer dimensions of 32. 5" W x 10. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 29. 75" x 7. 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