34" x 36" Cube Core Eggcrate Return Air Filter Grille for 1" Filter RV Mobile Home + Product Details Size -

+ Product Details Size - 20"w X 6"h is the size for the duct opening measurement only

+ Product Details Size – 18" x 30" or 30" x 18" is the size for the duct opening measurement only

actual front end outer dimensions are approximately 28 5/8" width X 30 5/8" height

+ Product Details Size – 10"w X 22"h is the size for the duct opening measurement only

+ Product Description Upgrade your ventilation with our premium grilles and registers

34" x 36" Cube Core Eggcrate Return Air Filter Grille for 1" Filter RV Mobile Home + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 34" x 36" OR 36" x 34" duct opening (measured at the opening), with actual outer dimensions of 36. 5" W x 38. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 33. 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