If it was made as some sort of cheap/inexpensive flare & signaling device I can see where it might have some market and use as a hikers friend, fisherpersons and the like.
At the current price, it wouldn't make it in that market for sure.

...$400 for a s/s self defense weapon?,,no.
That's just a false sense of security for the person carrying it and that generally leads to very serious situations, injurys and the worse.
It's may tickle the fancy of the latest 007 fan but the world is real and nasty, quick and dirty.

Better to spend the money on a decent firearm,, and some SD classes if you're serious