Fitting for copper and plastic

[ROBERT V. YOUNG]

If I am not mistaken it is a copper to cpvc fitting.
It takes a special glue but it is common in Montreal home box stores.
Pex has the same type of fitting only internal and clamp, not external ( meaning out side gets glued to copper fitting. )
With pex it compression and clamp fittings.
Copper male barbed fitting inters pex and is crimp-clamped.
copper fitting for cpvc -cpvc is inserted into copper female after being glued and held for 10-20 seconds.

[ROBERT V. YOUNG]

I hope this helps.
I have been looking at pex and polyB.
Here is a link that should answer your question about that linkage.
http://www.google.com/imgres?imgurl=...1t:429,r:6,s:0