36" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Material_Aluminum Actual Filter Size – 31

Actual Filter Size – 31 3/4"w x 11 3/4" x 1"

+ Product Details Perfect Fit & Easy Sizing - Designed for a 20" x 16" OR 16" x 20" duct opening (measured at the opening)

+ Product Details Size – 28"w X 30"h is the size for the duct opening measurement only

with actual outer dimensions of 26

sans-serif

36" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Material_Aluminum Actual Filter Size – 31+ Product Details Perfect Fit & Easy Sizing Designed for a 36" x 8" OR 8" x 36" duct opening (measured at the opening), with actual outer dimensions of 38. 5" W x 10. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 35. 75" x 7. 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