Now the power; we hardly believe that such a small thing can emit a powerful beam and effective! Nothing to say about the most powerful fashion is a true wonder.
The less powerful modes are obtained by removing a bit of the head lamp; we regret that the movement is not blocked for this maneuver; This is not inherently annoying but when used for the first time, it seems not to switch modes properly.
A good choice of varied modes; no complaints either on that, except that the SOS mode is a bit slow for my taste.
When the autonomy ... With a simple LR6, one holds the lamp on for a period quite respectable! The data announced on the manufacturer's website are realistic. However, in several months of almost daily use full power, I have not yet had to change the battery.
Finally, a real wonder; if you opt for a compact lamp, ergonomic, not greedy and powerful, this is the one!