I bought this body running light because I go running early in the mornings and because it is winter time, it is dark. The light got 3 different light stages, is easy and light to wear. I only used the light 4 times so far so I can't say how long it lasts. Together I have been running around 3 hours and the light is still working; didn't need to charge it yet. It doesn't make much difference whether I run with stage 1, 2 or 3 as the light doesn't come up much stronger really which might be a tiny minus. For runs up to 4 hours and/or back up in addition to a head light it is perfect and I would definitely recommend it!