[TowerTalk] PVC pipe

[Hank P]

Seems like someone here knows something about most anything so here goes....

I picked up on a walk a piece of what looked like 1 inch PVC pipe – but it is very stiff – looking in the
end it has 12 semi square “tubes” (little like  a honeycomb cross section) forming about a 3/8 inch center “pipe ” 

This stuff would be much better for cross arms etc than normal PVC . .

I googled for about a half hour and cannot find any reference to this stuff. 

Anybody know what this stuff is called so I can learn more about it ?
It has no markings on outside , shiny white like furniture grade PVC.

73 Hank K7HP