Telescopic Underfloor Cavity Vent With Air Brick Ventilator Black

At the time of purchase I didn't see many options for these at all and when I received this it was much more narrow than the vent in the wall so I had to use tape to fasten it to the existing vent and make sure all air was directed through this device.Also bought this with the extension so that I can route this out of the wall down the back of a sofa underneath the sofa out towards the front door. The difference is not huge but it's better than the wall vent blowing at the back of a sofa.