24" x 16" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w8h8 + Product Details Size -

+ Product Details Size - 4"w X 36"h is the size for the duct opening measurement only

+ Product Details Size - 24"w X 12"h X 2"d (for duct opening measurement only)

75"H – fits a 12" X 12" duct opening

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

24" x 16" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w8h8 + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 24" x 16" OR 16" x 24" duct opening (measured at the opening), with actual outer dimensions of 26. 5" W x 18. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 23. 75" x 15. 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