My bike broke the day this light set came in the mail.  That might make you think it wasn't useful, since I haven't had a bike since, but that isn't true at all.  This light has a low powered LED mode for when the batteries run low, and it can last nearly a week left on when in that mode, bright enough to do autorepairs under or navigate around the woods.  I use this light during blackouts, as a nightlight and as an emergency hazard light in my car since it has a strobe feature(the headlight I mean).  The taillight is useful only for a rear hazard light that I keep in my back window ever since the electrical system in my car went out and I was stranded with no hazards to warn other drivers.  Even the taillight is bright enough to use as an annoying red flashlight in an emergency (an I have).  The only downside to this light is that there is a nicer one, also by Bell, but I was too late to get it as I already have this one.