24" x 34" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Filter Grille By simply measuring the width

By simply measuring the width or the length of the vent

+ Product Details Perfect Fit & Easy Sizing - Designed for a 24" x 16" OR 16" x 24" duct opening (measured at the opening)

Design – Heavy gauge steel

+ Product Details Size - 36"w X 18"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 20 5/8" width X 10 5/8" height

24" x 34" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Filter Grille By simply measuring the width+ Product Details Perfect Fit & Easy Sizing Designed for a 24" x 34" OR 34" x 24" duct opening (measured at the opening), with actual outer dimensions of 26. 5" W x 36. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 23. 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