In a message dated 1/11/2004 6:45:32 PM Eastern Standard Time, Akimbo71@gmx.net writes: but I am afraid that this isn´t what I am looking for. The tubes I´ve got are ridged the complete lenght, You've exhausted my knowledge. I haven't seen such a tubeset with ridges/ribs the entire external length of the tubes, but I have to believe that one of the 1000 listmembers knows about this and will chime in. Lou Deeter, Orlando FL