8" x 34" or 34" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 10.5" X 36.5"] 18" Round Duct Pipe + Product Details Size -

+ Product Details Size - 26"w X 12"h is the size for the duct opening measurement only

Actual Filter Size – 23 3/4"w x 21 3/4" x 1"

75"H – fits a 10" X 10" duct opening

& EN 13180 standards

also called T-Bar systems

8" x 34" or 34" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 10.5" X 36.5"] 18" Round Duct Pipe + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 8" x 34" or 34" x 8" duct opening (measured at the opening), with actual outer dimensions of 10. 5" W x 36. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 7. 75" x 33. 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