I bought this welder mainly to weld steel, it didn't say in the specification that it had an internal shield gas shut off valve that's operated by the mug torch. But after watching a few YouTube videos it looked as if it did, when it arrived I was pleasantly surprised to find it did as I wont be using it with baseless wire. As an experienced welder I was impressed at how easy it is to set up & use ! My only complaint is that the digital displays don't go down to zero, so I doubt there accuracy ? Overall a fantastic piece of kit for the money, I paid £195 delivered for mine. It far outperforms my old wire wound based welder, but to be fair that was 30 years old when it packed up ! I genuinely believe that a novice welder could produce acceptable welds with a little practice !