10" x 36" or 36" x 10" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 12.5" X 38.5"] Fixed Blades with Damper Actual Filter Size – 15

Actual Filter Size – 15 3/4"w x 17 3/4" x 1"

The powder-coat finish lends a smooth

and Diffusers

Actual Filter Size – 35 3/4"w x 21 3/4" x 1"

+ Product Details Perfect Fit & Easy Sizing - Designed for a 18" x 20" OR 20" x 18" duct opening (measured at the opening)

10" x 36" or 36" x 10" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 12.5" X 38.5"] Fixed Blades with Damper Actual Filter Size – 15+ Product Details Perfect Fit & Easy Sizing Designed for a 10" x 36" or 36" x 10" duct opening (measured at the opening), with actual outer dimensions of 12. 5" W x 38. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 9. 75" x 35. 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