The advertised duration is with fluctuations to lower intensity levels. For example, at maximum intensity, it lasts about ten minutes and then drops to the minimum intensity. It works for reading a book inside the tent. For outdoor activities, it is not worth it.

3/9/2024 re-evaluation
I am coming back and correcting the rating after extensive use. Essentially, it is a headlamp with an intensity of 60 lumens. It gives 240 for a minimal time. But the basic (and only) use concerns the 60.

Regarding the use as a main flashlight for nighttime outdoor activities, it does not meet my needs, and I believe it is wrongly advertised for such use. (As a secondary or auxiliary light, it is very good and reliable.)

For any other activity that does not require higher lighting intensity (possibly fishing), it is ideal, and I would recommend it.

The flexibility of charging is also very useful; with 3-4 rechargeable AA batteries, the hours of use are realistically endless.