Lands' End Women's 3/4 Sleeve 1/2 Button Down Blouse

This shirt is stylish and versatile. The light blue color will blend with so many outfits. The half button down front has a hidden placket for the buttons. The sleeves also have buttons to open and roll up or cuff if you want. Looks to be about a size 6, but the tags do not show a size. Underarm measurement across chest is 39". Is a cotton shirt, but don't know the %.