32" x 16" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Color_Red Oak Wood + Product Details Size -

+ Product Details Size - 12"w X 18"h is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 36" x 24" OR 24" x 36" duct opening (measured at the opening)

+ Product Details Size – 12" X 4" is the size for the duct opening (floor/vent hole) measurement only

actual front end outer dimensions are approximately 26 5/8" width X 16 5/8" height

32" x 16" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Color_Red Oak Wood + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 32" x 16" OR 16" x 32" duct opening (measured at the opening), with actual outer dimensions of 34. 5" W x 18. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 31. 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