Anonymouswrote a review of Petzl Elios Helmet on October 26, 2007
The reason for the return on this helmet was that the back tightening knob began to disfuncion (it would no longer hold the track to keep the helmet at the selected head size).
I absolutely love this helmet, am using them for my programs, and this is the only issue I have had. I do not feel this is reflective on the brand or helmet type. This tightening device just was dysfunctional.