Ben Sherman Black White Striped Pea Coat Size M

Ben Sherman Black and White striped wool/poly blend coat. Has two front hidden pockets. 10 buttons: 5 false and the other 5 are used for closure. 25” long sleeves Shoulders are approx 15” wide. Approx 28” long armpit to armpit 17” So narrow at the top. But Ben Sherman tends to fit narrow and small. So not a typical medium. Size 6-8?