24" x 36" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 14" Diameter + Product Details Size -

+ Product Details Size - 22"w X 12"h is the size for the duct opening measurement only

Actual Filter Size – 27 3/4"w x 11 3/4" x 1"

+ Product Details Perfect Fit & Easy Sizing - Designed for a 18" x 12" OR 12" X 18" duct opening (measured at the opening)

+ Product Details Size – 16" x 36" or 36" x 16" is the size for the duct opening measurement only

actual front end outer dimensions are approximately 18 5/8" width X 32 5/8" height -

24" x 36" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 14" Diameter + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 24" x 36" OR 36" x 24" duct opening (measured at the opening), with actual outer dimensions of 26. 5" W x 38. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 23. 75" x 35. 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