Be advised, the Luxos-U is not completely waterproof. If water gets into the jack where the bar-mount thumb switch/USB port plugs in, it effectively becomes a disco light show until it drains its battery and the jack dries out. It helps to run the wire down under the light, then back up, forming a drip loop under the light. Unplugging the remote switch and using the rubber plug is not an effective countermeasure, since it doesn't fit tight enough to prevent wicking water in. What I've found it that leaving the jack open--nothing plugged in at all--works best in the rain.
Just a FYI, thats no longer an issue on the current model.