34" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w36h36 8" Diameter Is The Size

8" Diameter Is The Size For The Duct Opening Measurement Only

actual front end outer dimensions are approximately 27 5/8" width X 8 5/8" height

+ Product Details Size - 16"w X 30"h is the size for the duct opening measurement only

See our separate listing for Butterfly Dmaper to Control Airflow

12"w X 3"h Is The Size For The Duct Opening Measurement Only

34" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w36h36 8" Diameter Is The Size+ Product Details Perfect Fit & Easy Sizing Designed for a 34" x 18" Or 18" x 34" duct opening (measured at the opening), with actual outer dimensions of 36. 5" W x 20. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 33. 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