Keep yer noggin safe!
Recently picked up this helmet after buying a new bike and I'm very pleased. It fits well and very comfortably, the ventilation is nice so you don't roast while you ride as well. Bern helmets fit a bit on the small size compared to other brands, but their size chart is totally accurate. I have a 7 1/2 hat size and the XL fits me perfectly.
Haven't hit my head yet (knock on wood), but the certifications are reassuring. As with any helmet, if you have a fall that you think "Wow, I'm glad I had my helmet" ALWAYS get it inspected.