"Funny" regulatory story on those. They are not legal in the US since the regulators decided they were fire extinguishers and then compared them to the rules for fire extinguishers. They noted the lack of a nozzle, gauge, and locking device and proclaimed them out of compliance. They also noted that there are fires the balls do not put out, which to be fair, is kind of true for everything except the heat death of the universe.
It's a shame. It would probably be a good thing to keep over a domestic laser cutter or 3d printer.
It's a shame. It would probably be a good thing to keep over a domestic laser cutter or 3d printer.