Prevents condensation water running back down the duct towards the fan. This could potentially cause a fault, therefore Airflow Developments recommends the use of a condensation trap in its ducting systems. This is in line with the best guidance from the domestic ventilation compliance guide. This product is for use with 125mm diameter round ducting. This product must be used with two round pipe connectors (Part 52644001) to connect the ducting to the trap. Part sold separately. Please check the dimensions in the downloads tab to ensure this product will fit on your duct. Preventing mould and condensation in the property also involves protecting from condensation in the ducting and unit.