J.Crew Shimmer Tweed Black Jacket size 4/6

Love this jacket but felt it fit a bit snug in the shoulders so listing this as 4, even though it is a 6 because of the slim shoulder cut. My other jcrew blazers are a 6. I loved this blazer so much that I bought it in an 8 and now reselling the smaller size. Excellent used condition, only worn a few times. Armpit to armpit measurement is 18”.