First a little info on me: I am 6'0' tall and and wear a 38B so I am long and broad shouldered. I also live in AK where summer riding can vary from warm and sunny to cold and rainy. I bought this jacket in an XL and couldn't be more pleased. With the liner out and vents open it is very cool and with the liner in it is very warm. I've ridden in 40 degree temps and a rain storm and stayed warm and dry. The jacket fits through the chest and shoulders and the sleeves are actually long enough. I'm so impressed with Joe Rocket products I'm planning to order pants from them. You can't lose with this jacket!