Anyone who buys a flashlight thinking that this new flashlight is somehow going to subvert the laws of physics is not thinking rationally. We all know that batteries have finite capacity, finite maximum discharge currents, and that LEDs generate heat and can easily overheat. It wasn’t that long ago that 350 lumens was pretty much the maximum you could get out of any single emitter with 2xCR123A batteries, and now here we are with 3000-4000 lumen single emitter lights running on 21700s.