Miller's 14 pin connections are all interchangeable with all their equipment. The Trailblazer's 14 pin receptacle accepts the foot control, hand control and finger tip controls for voltage or amperage. It also has 24 volts to drive a wire feeder. Not all of Miller's machines will have 24 volts to drive a wire feeder an example is the Syncrowave TIG welders. The HF box plugs into the Trailblazer receptacle and the remote control device plugs into the HF box. The one "problem" with the Trailblazer's one receptacle is to multifunction with the different controls and feeders. They have to be unplugged and changed. You can't leave them all plugged in at one time. Oh by the way, The AC arc is very good with the Trailblazer with a HF box.