[Excellent Airflow]: roof vents with backdraft damper still have an airflow of UP TO 75%, while other products on the market have an airflow of less than 50% and poor ventilation. [Easy Installation]: 8 inch vent includes a pipe extension located underneath the flange for connecting to flex ducting, and there are four holes in the panel, which can help you install on the 8inch bathroom exhaust fan roof jack more firmly. [ Protection]: High-quality galvanized steel to durability and long-lasting use. The high-performance polyester powder coating has strong resistance and excellent protection. [MULT-FUNCTIONAL]: roof vent for bath exhaust is constructed with high-quality material, is not only suitable for household roof ventilation systems but can also be installed in other ventilation systems on roofs, walls, and more. It is ideal for various home areas such as kitchens, bathrooms, and attics, can be used with 8 inch duct and exhaust fans for house ventilation., Weight: 4.6848230675 Pounds, Manufacturer: Prterver