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.
The G961 Vertical Extension Sleeve has been designed for use with the
Manthorpe Telescopic Underfloor Ventilator (G960).

Each extension sleeve allows the vent to reach a further two brick
courses vertically. The sleeve can also be fitted to the base of the
G960 to provide horizontal extension through larger cavities.