This is such a great piece of kit. I have a Georgian flat so the chimney is by no means perfect shape and this works really well. It was really easy to ‘instal’ myself
I used an old towel on top of the pillow. It made it a little more difficult to install, but the towel filled in tiny gaps. It’s was immediately clear the draft was sealed.
This is a good product and pretty much exactly what I was after. Installation was a bit fiddly and the tube handle came undone a few times but it seems pretty sturdy once in place.