34" x 28" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Filter Grille + Product Details Size –

+ Product Details Size – 28"w X 18"h is the size for the duct opening measurement only

+ Product Details Size - 26"w X 26"h is the size for the duct opening measurement only

Made of High Quality Aluminum That Will Never Rust

actual front end outer dimensions are approximately 26 5/8" width X 18 5/8" height

34" x 28" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Filter Grille + Product Details Size –+ Product Details Perfect Fit & Easy Sizing Designed for a 34" x 28" Or 28" x 34" duct opening (measured at the opening), with actual outer dimensions of 36. 5" W x 30. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 33. 75" x 27. 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