I use it for my caving trips. His faults: its autonomy a fair bit (do not forget a spare set of batteries for big releases ...) Above all, the beam is highly concentrated, which means that it illuminates very well but only where they lights. The light is not scattered outside the beam. For example, if you look straight ahead, the sides or the floor are black. To see where you walk, so you have to really look at your feet, if you can not see anything. I do not find it very comfortable for the progression underground. However, I really appreciate the ease of adjustment and power. In narrow beam, it can illuminate far.
