This is off topic, but a few thoughts on Zebralight headlamps:
1. Headband mount
I own both the Zebralight H53Fw AA Headlamp Floody Neutral White, and H600Fc Mk IV 18650 XHP50.2 Floody 4000K High CRI Headlamps. Just today I was using the AA model for a small repair job - a perfect hands-free illumination for such a task. After about 30 minutes I took off the headband, walked into the other room, and my wife immediately asked, "What happened to your forehead?" Well, anyone who has a Zebralight headlamp has experienced the two deep vertical and parallel indentations grooved you're your skull by the rubber headlamp mount. It isn't very comfortable after a long hike or bike ride either. I know they're cheap and simple, but maybe consider a redesign of something along the way of a quick clip plastic mount such as found on a Skilhunt?
2. Headlamp switch
Also consider a pinch type on/off switch also à la Skilhunt vs. the current tube-end switch which makes it easier to operate with one hand?