This helmet is far more than I expected it to be. I have a slightly more narrow egg than round and this helmet fits like a glove. I agree with the below post of no "mushroom effect" whatsoever. It is light, very comfortable, and has plently of ventilation. I live in FL and it is very comfortable in our hot/humid weather. I am about 59cm and the large is perfect w/out any looseness or voids that I have been left with from other products that fit you round heads out there. Buy this, you won't regret it.
It comes with a soft pseudo suede chin strap cover, this was disposed of shortly after unpacking.