12" x 10" or 10" x 12" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 14.5" X 12.5"] Fixed Blades with Damper actual front end outer dimensions

actual front end outer dimensions are approximately 27 5/8" width X 22 5/8" height

R value rating of insulation - r3

+ Product Details Size – 20" x 36" or 36" x 20" is the size for the duct opening measurement only

Ideal for Walls & Ceilings: Designed for seamless installation in standard 20" X 12" duct openings

Efficient Airflow Design: The slots are meticulously angled to diversify airflow in two directions

12" x 10" or 10" x 12" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 14.5" X 12.5"] Fixed Blades with Damper actual front end outer dimensions+ Product Details Perfect Fit & Easy Sizing Designed for a 12" x 10" or 10" x 12" duct opening (measured at the opening), with actual outer dimensions of 14. 5" W x 12. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 11. 75" x 9. 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