When the inevitable Alien sequel hits theaters, The Boring Company's new flamethrower would make for a pretty cool prop. The not-a-joke product is now on sale at $500 a pop—but act quick, because only 20,000 are being made.

Since The Boring Company began selling its flamethrower over the weekend, it's become one of the market's hottest items. In fact, the company's CEO Elon Musk revealed 1,000 were sold in just a few hours, and that figure has reportedly ballooned to over 8,000. If true, The Boring Company has already sold $4 million worth of flamethrowers.

Musk Tweeted about the flamethrower on Saturday, saying it's "guaranteed to liven up any party!" He then said buying a flamethrower is a "super terrible idea. Definitely don't buy one. Unless you like fun."

There aren't too many details about the flamethrower other than shipments start going out this spring. Surprisingly, owning a flamethrower in the U.S. is legal, though rules vary by state. In California, for example, a flamethrower is legal to own if the flame projected is less than 10 feet long.

The Boring Company is also selling a companion fire extinguisher should something go awry. But Musk claims it's the "world's safest flamethrower," so what could go wrong?