I think i got my tubing from Hzg8grl
and i just ran out. I kept a small piece and will measure up the Outer diameter for you here as soon as i find it as it seems to be hiding on me at them moment 
I should be the one thanking you, so thank you and welcome Melissa! Now'll you'll have a new toy to play with
As Lisa mentioned too, she also carries the Super T line so that's another outlet to get your Super T Products at.
Dave,
I'm just posting the following information so people can compare it to whatever tubing spec's you post!
The tubing specifications (mentioned in the above posts) for part number "-424" available from Omeg.com is 4mm OD x 2.4 mm ID. The "-15" is for (length) 15 meters of tubing.
Thanks
PK
My tubing that fits great in the bottles i include with the vapemate measure 5/32 or approx. .155
In the part number builder (1) is -424 (2) is -15 and (3) is left blank if you want clear. Glad to help.
Does anyone have a pic of the vapemate on a Darwin? Curious how the setup would look. Would really appreciate it!
I thought i saw a pic floating around as well with it on the Darwin, but i can't recall if it was buried in this 100 page thread or not ;-)