The helmet fits well breitern head, since he is further cut.

My son has with his 2/2 years a head circumference of 51cm. Thus, I was inclined to buy the next size up, but this is a bit wider when his helmet colleague in the next size and it fits perfectly. Granted, it was my Favourit design technically, but my son said that he was the best and did not want him to take it off, so I think to myself, "that's a good sign ..."

Only consideration:
The helmet has large air excerpts with großmaschigem power supply, which is great for air circulation. But if the sun on the helmet "pops" is probably inevitable sunburn in sun-sensitive children ...

His helmet successor has tapered air excerpts where this problem been remedied - shortcoming - no great cheese mouse motif. :)

So decide for themselves. I thought my idea could possibly be helpful in your decision making.