I’ve had two mass drop torch/flashlights such as this, the first was the titanium version and the button failed after a week, the same has now happened to this one, 3 uses and it quickly flashes then nothing with each press. However if I swap the tail cap for the one from another copper torch/flashlight it works. Seems an issue with the switch. I have a Reylight pineapple I have carried in my pocket for over 2 years, beaten almost to death and dropped in 5m of water with no issues… these are let down by the lousy switch mechanism.