I have tried on about 50 helmets (no exaggeration) from so many different brands and some the same helmet but in two sizes. I have an oval shaped head. I originally bought an LS2 the same as my husbands but after sitting with it on for an hour, I started to feel pressure on the top and front of my head despite it being a size small but my head measures extra small. He find his LS2 so comfortable but he has a round head. I saw another review on this scorpion helmet where the guy sent it back and got an LS2 where as I have done the opposite. I am in between a size XS and S. XS was too snug and the S was only slightly too big BUT after adding a balaclava and pumping up the cheeks with the airfit system, it is a perfect fit. Finally I have a helmet that fits and with glasses too. No pressure points and the material inside is so soft. No problem with ventilation and is light to wear being carbon. If you’re struggling to find a helmet with a small oval shaped head, then try this one. I did have to fiddle with the chin strap a lot to make it tighter as even fully done up it was loose. Quick you tube video helped with that. Thank you to the Boston crew for getting so many helmets out for me and for suggesting the balaclava. It made all the difference. Very happy with my lovely new helmet!