The message .com
from "marbles" contains these words:

Am I missing or not understanding something?

You can get a mandrel tool which expands the end of a pipe so the street
fitting plugs into it.

However, in the case of BQ it's probably 'cos some arse in head office
has noticed they're marginally cheaper so is flogging them while not
understanding what the difference is.

--
Skipweasel
Pay no attention to that man behind the curtain.