I've tried the regular 3mil metal tube, colored. I put it all together, FILLED it with delicious juice, thought "wow this looks SICK", then it leaked ALL OVER from the bottom cap...
There's been other reports of this happening, so use them at your own risk. I think the threads are messed up on some, don't quite seal right..
I just ordered 3 diff colored metal tubes for my mini vivi novas & I'm crossing my fingers that I don't have the same problem..
~Vaping is a lifestyle~