Different model numbers leads to a lot of confusion, thats obvious but, the brand name units found at the box stores work well and truth be known I would rather have taps in most cases. I probably am "qualified" for lack of a better word to tune the machine very accurately with infinite voltage setting but,,,, it don't make any difference and is so much simpler. I run 030 in a SPT Lincoln, a 180 class unit, use 3 settings as its only got a 5 speed, but they are really tuned for this size wire, "B" 2 1/2 for thin, "C" 3.5 for medium and "D" 5.5 wfs for max, on occasion I touch the wire speed for special project but its rare. I might back off the wire speed a pinch for some overhead, etc.