Woman's Short-Sleeve Polo-neck Angora Sweater by J.Crew

Beige short-sleeved polo-neck 3/4 button-front pullover angora sweater by J. Crew

Small (38)

This is a cling-fit design, so there's a good amount of stretch to it. The measurements are taken lying flat and expanded to a comfortable margin. 

Size tag reads "Medium," but the chest only measures 38"/96.5cm, which is closer to a size Small.