Bell Frozen Toddler Bike 3D Tiara Helmet (3-5 years)

It is really the helmet's fault my daughter falls right between sizes? Maybe. It's a SUPER cute helmet and she loved that it has Frozen AND a tiara built in. She was dying to wear it with her Big Wheel. We debated on which size to order and this was the one that technically aligned with her measurements. I think it is too small though. I can cram it on her head, but the chin strap barely buckles. I'm worried the larger sized version will be way too big, though, because according to the measurements it is going to be swimming on her. I think what we really need are these dimensions for circumference with a longer chin strap. So, in a way, I do think it is the product's fault that it doesn't fit. It comes in two versions and I think they didn't allow enough flexibility in design to accommodate all the head shapes that fall into the gap between their sizes.