Size Medium, weighing 1350gr and fits like a glove on the head (57.5cm). Perfectly balanced helmet that you don't feel like you're wearing (coming from STR - so you understand it's day and night). Among the pros that should be mentioned is the large field of view of the visor - the over the shoulder looks are now more comfortable, which automatically translates to greater safety on the road. Also, among the cons is the sunvisor, which blocks the sun without distortions. I will speak as a naked bike rider, and I must say that you can reach 100 without realizing it, mainly by the sound of the air - in other words, it won't hurt your ears. Aerodynamically (again around 100), it is very stable and does not strain the neck. It is worth the extra 400. Get it with your eyes closed.