10" x 26" or 26" x 10" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 12.5" X 28.5"] Aluminum - Cube Core Actual Filter Size – 11

Actual Filter Size – 11 3/4"w x 15 3/4" x 1"

+ Product Details Size – 22" x 26" or 26" x 22" is the size for the duct opening measurement only

actual front end outer dimensions are approximately 27 5/8" width X 34 5/8" height

Can be hooked up with our "Butterfly Dampers" for precise airflow control

10" x 26" or 26" x 10" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 12.5" X 28.5"] Aluminum - Cube Core Actual Filter Size – 11+ Product Details Perfect Fit & Easy Sizing Designed for a 10" x 26" or 26" x 10" duct opening (measured at the opening), with actual outer dimensions of 12. 5" W x 28. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 9. 75" x 25. 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