Manthorpe Castellated In-line Roof Tile Vent - Dark Brown Properties Free airflow: 10000mm2. Length: 418mm. Width: 332mm. Top material: uPVC. Base material: polypropylene. Designed for use with: Marley Ludlow Major, Redland Renown, Sandtoft Lindum, Russell Cheviot and Lagan Square Top interlocking tiles. Features In-line and discreet low profile design. 4mm louvred flyscreen grille. Integral sidelock clip to ensure secure fit. Range of colours available. Profiles suit top all top tile manufacturers. Fully independently wind tunnel tested. Base outlet feeds directly into roof space. Adaptor available for mechanical extraction. Suitable for use down to a 20° roof pitch. The Manthorpe Castellated in-line tile ventilator is designed to provide a quick and simple solution to the problems of roofspace ventilation and mechanical extraction / soil stack termination through a "square top" profile tiled roof. The profile vent is designed to replace a single tile and maintain an unbroken appearance to the roofline whether used at high or low level. The tortured path through the 4mm louvred grill and internal weathering geometry is designed to maintain a 10k mm² of airflow whilst channelling any water ingress out of the vent and on to the roof covering.