Large Slate Vent is a large capacity ventilating slate to suit 600mm x 300mm (24” x 12”) and 500mm x 250mm (20” x 10”) double lap slates, man-made or natural, for roofs with a pitch over 20°. Key features Low profile design makes it unobtrusive on the roof line Fits perfectly with adjacent slates Slate grey cap blends in with most man-made or natural slates Built-in downpipe to ensure direct ventilation path into the roof space Fully wind tunnel tested Adaptor and flexipipe available for soil ventilation or mechanical extraction Prevents entry of birds and large insects Area of application For roof pitches 22.5° and over. For 600mm x 300mm (24” x 12”) and500mm x 250mm (20” x 10”) natural double-lap slates and man-made fibre cement slate tiles. High and low level ventilation.