18" x 34" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Supply Grille actual front end outer dimensions

actual front end outer dimensions are approximately 12 5/8" width X 8 5/8" height -

Actual Filter Size – 19 3/4"w x 29 3/4" x 1"

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

Actual Filter Size – 21 3/4"w x 35 3/4" x 1"

+ Product Details Size - 20"w X 12"h is the size for the duct opening measurement only

18" x 34" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Supply Grille actual front end outer dimensions+ Product Details Perfect Fit & Easy Sizing Designed for a 18" x 34" OR 34" x 18" duct opening (measured at the opening), with actual outer dimensions of 20. 5" W x 36. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 17. 75" x 33. 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