I hesitated to take the S or M size, my daughter having a head circumference of 50cm. In the end I took S and it was the right choice as the helmet is adjustable !! so it suits him perfectly and he can go even longer! The quality is very good, it is super light, and perfectly faithful to the design drawing, it is even more beautiful in real life. So this is a purchase that I highly recommend, there is nothing to add! Good ballads!
