When you first see the movie you say that something like the triton artificial gill could be possible, but after you hear Thunderf00t explaining it, you know it’s bull. Such a small device cannot be a rebreather as it does not have the required volume and also cannot process the huge amounts of water in such a small space and with such a small battery.
Thunderf00t is an American researcher in Chechoslovakia, working at a nuclear plant, and he has already written a number of scientific papers, one of them being about the explosion of sodium in water.
He also debunked a number of other “inventions”, like the thorium car or solar freaking roadways, so stay close and listen to what he has so say.