This iron replaces one of the radio shack style. I have had a number of other butane soldering irons before, and hated them. They were very difficult to light, the tended to go out, they leaked butane quickly when off, so you had to fill it before each use. This one, so far, has none of these problems.
And MAN! what a great difference the Weller ML500MP Mini Butane Soldering Iron one makes. It fires up with ease. No more flicking the bic to get the iron going. Heats up fast and is ready to solder in just a min. Gets hot quickly, wide amount of adjustment, reliable ignition, this is the absolute best of the dozen or so pen soldering iron brands Ive tested. Cools down pretty fast too.