MagicShine. Action LED sells them, and the head-straps, helmet mounts, etc. High power is claimed at over 800 lumens, but most testers say actual lumens is closer to ~500. I need more light than most. I find one MagicShine just adequate. Most will find it plenty of light. For hiking/working on the bike/working on the car, you need less light. In any case you cannot use the default high power setting unless you are moving at bicycle speeds. The thermal protection circuit shuts the light down if you run the light on high power for more than about 5 minutes on high power just standing around. I find the lowest power plenty for doing stuff in the dark and the middle power setting is brighter still and does not trigger the thermal protection. What more do you need to know? Get that credit card out already. Do I need to find the link for you too? Ok, here it is: BIKE LIGHTS ? Action-LED-Lights