Mackenzie Martinwrote a review of Petzl Zipka Headlamp on April 24, 2017
Familiarity: I've used it once or twice and have initial impressions
I took this down to Moab this weekend, and I was impressed right away. I have another Petzl headlamp, but I am always adjusting it to fit on my head with a hat, without a hat, with a helmet, etc. Needless to say, I was excited to have an auto-adjusting device, and the Petzl Tipka didn't disappoint.
GLOW IN THE DARK. The headlamp glows (when it's off) so it's easy to find in your pack, etc. A killer extra feature that shows Petzl's dedication to innovation and functionality--very impressed.
Slips off ... When I was going sans hat or helmet, I found that it would sometimes slip off my head/hair. Maybe my hair is just silky smooth and this is user error (kidding). In all serious, though, I would be a bit worried about having this slip off when I was climbing or doing another activity.
All in all, this is a rockstar device at an amazing price.