Sorry been away for the last few weeks and just saw this.
Meh, not powerful enough for my liking.

BTW I don't condone this sort of practice, very very dangerous and people shouldn't be trying things like this.

Eyesight could be lost in one or both eyes before you could even blink with such high powered devices.
Actually I know of that guy who made the video (styropyro).
Have a look at this one he made: