The Easifit Ventguard is secured to the airbrick by means of a special catch which is shown below.
This catch is a small steel bar set in a slot in the end of the threaded rod. This bar can sit in either a horizontal or a vertical position.
When fitting or removing the Ventguard you set the bar to the horizontal position. This allows the rod to be inserted through the airbrick or removed after fitting.
When tightening the Ventguard into position you set the bar to the vertical position. This prevents the rod being pulled out of the airbrick. You can then compress the Ventguard against the outside face of the airbrick by turning the handle.
The position of the bar is set by simply turning the threaded rod clockwise or anti- clockwise.