Klober's 20k Slate Vent is a large capacity Universal Tile Vent that suits most concrete interlocking roof tiles (600mm x 300mm and 500mm x 250mm) that can be used to ventilate roof voids. Perfect solution for heat recovery systems with 150mm adaptor. Fits perfectly with adjacent slates. Features and Benefits Provides 20,000mm² effective ventilation Low profile design makes it unobtrusive on the roof line Fits perfectly with adjacent slates Built-in downpipe to ensure direct ventilation path into the roof space Fully wind tunnel tested Adaptor will be available for soil ventilation or mechanical extraction Prevents entry of birds and large insects Perfect solution for Heat Recovery Systems with 150mm adaptor Complies fully with relevant Building Regulations and British Standards. Product Specification Length: 600mm Width: 380mm Depth: 91mm Material: Rigid PVC Colour: Black (matte finish) Area of application: 600mm x 300mm (24” x 12”) and 500mm x 250mm (20” x 10”) double lap slates. Roof Pitch: Roofs with a pitch over 22.5°