It was a good stunt, too, even if it started as a joke. The Boring flamethrower even managed to annoy a California lawmaker, who wanted to ban it because—well—it might cause fires.

Musk had about 20,000 of the units for pre-order, and he tweeted Thursday morning that they were all gone.

Flamethrowers sold out

— Elon Musk (@elonmusk) February 1, 2018

And because—this cannot be stressed enough—flamethrowers throw flames, Musk added that each one of the things would ship with a free fire extinguisher.

All flamethrowers will ship with a complimentary boring fire extinguisher

— Elon Musk (@elonmusk) February 1, 2018

If you’ve understandably lost track of which Musk venture The Boring Company is, it’s the one that wants to suck people at high speed through underground vacuum tubes, as opposed to the one that wants to hurl them around the world in a “Big F***ing Rocket” (that’s SpaceX), the one that’s trying to speed up the development of artificial intelligence in order to save the world from killer robots (OpenAI), or the one that builds electric cars, batteries and other annoyingly practical stuff to do with renewable energy (Tesla, also known as the day job).