18" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w34h34 16"w X 3"h Is The

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

+ Product Details Perfect Fit & Easy Sizing - Designed for a 20" x 14" OR 14" x 20" duct opening (measured at the opening)

actual front end outer dimensions are approximately 36 5/8" width X 10 5/8" height

Actual Filter Size – 13 3/4"w x 33 3/4" x 1"

Quality Packaging - Carefully Shrink Wrapped with Cardboard Backing to Prevent Damage in Shipment

18" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w34h34 16"w X 3"h Is The+ Product Details Perfect Fit & Easy Sizing Designed for a 18" x 8" OR 8" X 18" duct opening (measured at the opening), with actual outer dimensions of 20. 5" W x 10. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 17. 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