4 Inch to 3 Inch Duct Reducer, Bathroom Fan Duct Adapter Connector

[Smooth Size Transition] This duct fitting converts 4 inch duct opening to 3 inch port, ideal for bathroom exhaust fan and daily ventilation applications. It stabilizes airflow and effectively reduces air gap leakage, perfect for household and general HVAC ventilation use. [Wide Range Compatibility] Compatible with most common bathroom exhaust fans and household ventilation systems as well as standard duct pipes. Fits 4 inch fan outlets and connects smoothly with 3 inch duct tubing, suitable for new installation and part replacement. [Effortless Installation] Simply mount the reducer onto 4 inch fan outlet and connect with 3 inch ductwork for quick setup. Easy to secure without complex professional tools, helping save installation time.