Great Jacket! Flows tons of air fits like a glove. Its like you dont even know you are wearing it. As far as size? I dont know how an is fitting in a 54 euro. Im 5 11 200 lb semi athletic build and got the 56 euro. I like to be able to move a little and if you want to wear the chest protector you need some room. So to me the back protector is a joke for this caliber jacket and I swapped it out! The zippers are on the small side too. The quality is top notch though.