This is quite possibly the greatest jacket of all time. i ordered it with the "layered luna dress" in grey, and i am now giddy with excitement to wear the combo! very chic. i am confident this will be a staple in the years to come. for reference, i ordered my normal size xs (5'5, 115 lbs, muscular) and did not find it to be too tight in the arms (and i have fairly broad shoulders). i did not try it on with long sleeves, but i still think there would be adequate room.