34" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Compatible With Duct 12in + Product Details Size –

+ Product Details Size – 34" x 36" or 36" x 34" is the size for the duct opening measurement only

24"w X 6"h Is The Size For The Duct Opening Measurement Only

+ Product Details Size - 8"w X 16"h X 2"d (for duct opening measurement only)

+ Product Details Size – 30" x 34" or 34" x 30" is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 28" x 6" OR 6" x 28" duct opening (measured at the opening)

34" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Compatible With Duct 12in + Product Details Size –+ Product Details Perfect Fit & Easy Sizing Designed for a 34" x 8" Or 8" x 34" duct opening (measured at the opening), with actual outer dimensions of 36. 5" W x 10. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 33. 75" x 7. 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