Duct Reducer
6" Round to 4" Round Duct Reducer Genuine Broan® Parts meet rigid engineering and test criteria and are equal in design to your original Broan unit. Replacement parts made by other manufacturers might not last as long as Broan parts and typically aren't built to your unit's exact specifications, which could lead to problems and/or other part replacements. It is also important to note that using anything other than Genuine Broan Parts will automatically void the warranty. Features: Reduces 6" Duct to 4"