i spoke with one of there techs and he said that the arcforce replaces the regular shunt's in your machine from the way i took it gives you more heat ranges, for instance your selctor switch has 5 pos. it adds 5 heat ranges to each position so you got a total of 25 heat ranges sounds like a good upgrade to me. just thank if you put there 7 selector coils in you would have 35 heat ranges. you couldnt go wrong, the way he explained it to me you would have softer arc 0,1,2,3 being normal,4,5 being stiffer arc.