The G960 Telescopic Underfloor Void Ventilator is designed to provide a clear airflow passage to the void underneath a suspended floor. The telescopic feature enables the ventilator to adjust vertically between three and five brick courses. The right airflow can be achieved when the ventilator is used with a Manthorpe G930 Airbrick. The aperture can also accept a standard clay airbrick, although the airflow is reduced.