This is hotly contested on the forums, but the xhaler supposedly can switch between 5 and 6v by screwing the knob on the bottom in or out.
The design of the knob, along with the material it is made from, is supposed to accomplish this. I've read that other 5v
mods use electrical resistors which can burn out or fail.
My xhaler is the love of my life...for now. But I am very fickle.