26" x 36" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w18h18 actual front end outer dimensions

actual front end outer dimensions are approximately 22 5/8" width X 20 5/8" height -

+ Product Details Size – 36"w X 28"h is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 14" x 10" or 10" x 14" duct opening (measured at the opening)

+ Product Details Outer dimensions: 17

+ Product Details Size – 25"w X 10"h is the size for the duct opening measurement only

26" x 36" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w18h18 actual front end outer dimensions+ Product Details Perfect Fit & Easy Sizing Designed for a 26" x 36" OR 36" x 26" duct opening (measured at the opening), with actual outer dimensions of 28. 5" W x 38. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 25. 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