The Hambleside Danelaw soffit and fascia product ranges provides roofspace ventilation at the lowest level of the roof line. All grille and mesh sizes are designed in accordance with the recommendations within BS5250. These vents help to avoid excessive airflow resistance and prevent the ingress of birds and large insects. HD 12000u Our universal over fascia vent provides a through-flow of ventilating air over the fascia board in both new build and refurbishment details. Conforming to standard flyscreen regulation requirements, this vents rounded front sections prevent blocking of airflow from overlapping underlay.The HD 12000U features a unique two stepped fixing position to allow for use on roofs above and below 15° pitch. Reinforced nailing guides ensure accurate fixing. Properties Airflow: 25,000mm2 airflow per metre at 25mm fixing position.10,000mm2 airflow per metre at 10mm fixing position.Length: 1m.Width: 48mm.Height: 36mm.Material: polypropylene.Colour: black.