Kyle Smythwrote a review of Stan's NoTubes Tubeless Valve Stem - Pair on May 31, 2018
Familiarity: I've put it through the wringer
So it's 2018 and if you prefer to ride your bicycle on dirt or gravel, you should be riding without tubes. Once you have come to terms with that, you should get yourself two sets of these gems. One to aid in setting up your wheels and proper tires tubeless and one set for your tool box or to convince your riding buddy that they should go tubeless as well.
Unlike some other silly shapes that other valve stems may have at the bottom, these circular ones work great with every rim that I have tried them on, and they do a damn fine job.
There is a reason that people that don't run tubeless still know who Stan is, his stuff is class defining for sure!