30" x 34" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 10in diameter + Product Details Size -

+ Product Details Size - 36"w X 8"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 36 5/8" width X 14 5/8" height

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

actual front end outer dimensions are approximately 20 5/8" width X 36 5/8" height

Works for all Air Conditioning applications including Ductless Mini-Split

30" x 34" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 10in diameter + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 30" x 34" OR 34" x 30" duct opening (measured at the opening), with actual outer dimensions of 32. 5" W x 36. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 29. 75" x 33. 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