8" x 6" or 6" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 10.5" X 8.5"] d + Product Details Size –

+ Product Details Size – 6" x 28" or 28" x 6" is the size for the duct opening measurement only

+ Product Details Size - 34"w X 20"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 12 5/8" width X 28 5/8" height

Installs Directly On Round & Oval Spiral Duct - No Frames

8" x 6" or 6" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 10.5" X 8.5"] d + Product Details Size –+ Product Details Perfect Fit & Easy Sizing Designed for a 8" x 6" or 6" x 8" duct opening (measured at the opening), with actual outer dimensions of 10. 5" W x 8. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 7. 75" x 5. 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