The Acerbis is a nice jacket, but is sized a little small. When ordering, go up one size, especially if you want to wear it over your chest protector. I wear large in jerseys and chest protector, but went with an X-large in the jacket. I think that a large would have been a bit snug (I am 5 9', 180 lbs). The jacket can have a liner added to it, as well as shoulder and elbow pads that snap in. The jacket does have vents in it, but still is a little warm, even without the liner. It does shed water well, but I havent ridden in any torrential downpours to see how protective it really is. I like it and only paid $105 for it to my door.