What I'm after is a piece of plastic pipe which will slide within
100mm extractor hood ducting.

Reason being that I've drilled a 117mm hole in a wall to vent a tumble
dryer. And the tumble dryer has (literally) about 15mm of gap between
it and the external house wall - nowhere near enough room to mount a
flexible tumbler dryer hose outlet.

What I can do is push the 100mm pipe directly onto the tumble dryer
outlet (which is on the side of the tumble dryer) - and that works
perfectly well. Only problem is that the tumble dryer is then "fixed"
to the outside wall of the house and can't be moved without first
pulling the 100mm tube away - breaking all seals between the 100mm
duct and the cavity wall in the process.

This problem would be solved if I can get hold of a piece of (e.g.)
95mm tube which can gracefully slide within the 100mm ducting, and
thus mate up with the tumble dryer outlet. But does anyone manufacture
ducting of a suitable size?

I know this is a pain in the arse arrangement, but I'm running on
empty with regard to how this problem might be solved. I've got no
options with regard to creating a bigger gap between the tumble dryer
and the outside wall because of the furniture arrangements in the
utility room - so somehow I've got to bridge the small gap between the
tumble dryer and the wall.

PoP