Don't know what it is. Maybe spend a few bucks more and get a better one and then tell me how it works. Because I warned you about it. It basically works when it wants to, using a set of batteries about every solder joint or two. The maximum I got was three wires on a set of batteries. And I've had it for many moons and I've been waiting to see it. I researched as much as I could and got more from reviews and YouTube. I'm not done with this device yet. Always have my plug or backup butane handy. This one just doesn't cut. But it helped me with my patience because I really wanted to smash it with a hammer many times. I really miss her for $12...