I have one that I have found to be useful for fishing. I normally wear a cap then anyways and they are so light that you don't really notice them. They come with and use (4) 2016 batteries, and are not as bright as my innova micro althought they do provide a good flood with the 3 led's they have practically no throw. Battery life is listed as 24-48 hours....I would say useful for maybe 8-10 hours. The switch on the side is easy to access and I normally just keep mine off until needed and then turn it back off to save the batteries. I think these are using rather outdated led's which are quite blue in tint and there are probably better choices today...even with the cheaper led headlamps that take AAA or AA batteries. Still I wouldn't discourage someone from buying at the discount price as the batteries for these sell retail for 3.99 in the Cat's Eye 4 pack. I am not unhappy in my purchase as I have gotten quite a bit of usage from it...but again these are using rather outdated led's and there are definitely better choices in headlamps on the cheap today.