36" x 14" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w25h25 + Product Details Size -

+ Product Details Size - 24"w X 8"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 4

+ Product Details Size - 24"w X 24"h X 2"d (for duct opening measurement only)

actual front end outer dimensions are approximately 12 5/8" width X 20 5/8" height

+ Product Details Size – 6" x 10" or 10" x 6" is the size for the duct opening measurement only

36" x 14" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w25h25 + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 36" x 14" OR 14" x 36" duct opening (measured at the opening), with actual outer dimensions of 38. 5" W x 16. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 35. 75" x 13. 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