I also have a Snap On "touchless machine" that name is a bit of a misnomer though as it does touch the rim during dismounting & mounting (not while unseating the bead though). It clamps one of two ways :
#1 is 4 little arms nuematically spread outward pushing against the inside of the rim.
#2 you can start in the outward position with those arms, hit the button & they come in to grip the rim just inside the bead area.
I have done everything from the most expensive aluminum wheel to dually wheels with never a scratch. I just took the old tires off my 64 GP 8 lug wheels so I could paint them yesterday with no problem.
I don't have a computer balancer. I have Centra-Matics on the dually & use counter-act balance beads for most everything else. I do still have an old bubble balancer left from our gas station in 1982!
God Bless
Bill
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