28" x 28" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w12h12 + Product Details Size –

+ Product Details Size – 28"w X 26"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 10 5/8" width X 26 5/8" height

+ Product Details Size – 24"w X 16"h is the size for the duct opening measurement only

and the second number represents the height

+ Product Details Size – 29"w X 22"h is the size for the duct opening measurement only

28" x 28" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w12h12 + Product Details Size –+ Product Details Perfect Fit & Easy Sizing Designed for a 28" x 28" duct opening (measured at the opening), with actual outer dimensions of 30. 5" W x 30. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 29. 75" x 29. 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 Made from