I'm looking for a minimum thickness vacuum hose just to hold the dukes pressurization valve open on takeoff.  Right now I have a 1/4" i.d. .64" o.d. big fat rubber line.    I don't see anything on McMaster Carr that is thinner wall.  But given it probably needs to handle maybe 10 psi of vacuum, the big fat rubber hoses seem like overkill.

I was thinking something like the dh instruments dh400 might do but they seem to have been acquired by Fluke and Fluke doesn't seem to be selling the hose anymore.

Any suggestions?