PVC duct reducers commonly used in ventilation or air conditioning systems to connect pipes of different diameters, such as reducing a 150mm pipe to a 125mm one.They are designed to ensure smooth transitions in airflow, minimizing turbulence and pressure drops.Some versions of these connectors feature a multi-stage design, allowing them to be cut to fit various standard pipe sizes.They can also be used as condensation collectors or anti-condensation junctions to manage moisture in vertical ducts.