Review Item: 
Poor fit
poor ventilation

I have a small head, but I'm in the size range given by Petzl. I couldn't get the strap to fit properly because it isn't fully adjustable. Once I managed to figure out I could shorten it by improvising (wrapped it around the plastic thing at the back) the fit was alright. Another issue is that there are large gaps between the sides of my head and the helmet. I'm not sure what the consequences are in case of an accident. Lastly, the top of my head sometimes gets hot and itchy, which I think is due to a lack of ventilation in that area. I have the white model which makes me look too much like a mushroom. Keep in mind these foam helmets can only take one impact, so they're not ideal for ice climbing and mountaineering. Another potential issue is that a British mountaineering organization rated the impact forces much higher on this helmet compared to traditional designs.