18" x 30" or 30" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Copper Coil Actual Filter Size – 21

Actual Filter Size – 21 3/4"w x 29 3/4" x 1"

Powder-Coat Finish – Never rust

actual front end outer dimensions are approximately 26 5/8" width X 28 5/8" height

32"w X 8"h Is The Size For The Duct Opening Measurement Only

+ Product Details Size – 30"w X 12"h is the size for the duct opening measurement only

18" x 30" or 30" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Copper Coil Actual Filter Size – 21+ Product Details Perfect Fit & Easy Sizing Designed for a 18" x 30" OR 30" x 18" duct opening (measured at the opening), with actual outer dimensions of 20. 5" W x 32. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 17. 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