Features and benefits: • Efficient, unobtrusive and easy to fit • Can be fitted to existing soffit boards in situ • 4mm wide holes comply with BS 5250 : 2011 • Durable and totally resistant to decay • UV stabilised and colourfast Mainly used in refurbishment, push-in soffit vents (primary roof vents); provide a convenient method of providing ventilation through an existing soffit board. Barbed ridges on the sides of each vent grip the soffit board and hold them securely in place. Each ventilator provides 2000mm² of free airflow and should therefore be positioned at 200mm centres in order to achieve the equivalent of a continuous 10mm opening.