Taurin wrote a review of Mammut Burny Headlamp on October 27, 2012
Familiarity: I've put it through the wringer
the battery life of this light makes it unusable. I'd say it lasts a good 4 or five hours before it starts to crap out. batteries cost about 3.50 each, so I'm returning this light before I've spent more money on batteries than I did on the light itself.
I bought the Burny because I needed a new front light for my bicycle. The Burny is exactly what I was hoping for, and more. It is tiny, (an ideal size for a bike light in my opinion) and bright, clips onto a pocket/bag, stretches around handlebars, and has red and white light options. I love that you have to click the button twice to turn it on- this thing will NEVER turn on in your pack inadvertently. I'll be bringing it traveling and backpacking, as a backup light. Highly recommended.
Only one thing I don't like- it uses those nickle-sized CR batteries, which are not super-easy to replace. On the other hand, AAA or AA batteries would make it a much bulkier light.