My friend got one a couple of months ago. He said he liked it. I'll
have to ask him again for a more recent and updated review, now that
he's had it a few months. He said the soldering tip is actually two
electrodes. And when solder is placed across these little electrodes,
the solder completes the electrical circuit which therefore causes the
heat buildup. Once the solder is gone, the electrical circuit is broken
and you have a cold soldering tip again....relatively. That's all I
know about it for now.