Manthorpe G900 5" Core Ventilator White The Manthorpe 5" Core Drill Vent G900 is designed for use when ventilating a gas appliance, but can also be used for general through wall ventilation. The vent can easily be fitted in both refurbishment and new build situations with the use of a 5" (127mm) diameter core drill. The kit includes a cowl vent for exterior use, a louvre grille for inside, a 350mm length of pipe duct and an optional anti-draught baffle. This baffle reduces the airflow and also the feel of a draught through the vent. The external cowl minimises uncomfortable draughts, reduces noise and light from outside the property and acts as a barrier against wind driven rain whilst providing a free area of 100cm² and is available in both brown and terracotta. The Louvre fits on the internal wall and, similarly to the cowl, reduces draughts, noise and light penetration, while providing a free area of 100cm², it is only available in white. 10,000mm² of airflow without draught baffle 7,000mm² effective airflow with baffle Ventilate gas appliances (Image Shows Colour Brown)