The sleeving is from Sidewinder Computers. It's about the best I've seen around. I used the 1/2" sleeving for the tubes. This sleeving is stiffer and thicker than any other sleeving I've seen, so it helps the soft thin-walled tubing keep its shape. I think on my next build I'm going to use thicker-walled tubing. This stuff is nice and small, which is good for this build, but it is soft and looks like it will kink really easily.