Columbia Sportswear Chill River Tee. From the manufacturer: Built for active comfort with advanced wicking and cooling fabric, UPF 50 sun protection and just-right stretch. Size Small - Chest: 34-35", 24" collar to hem, 9" sleeve, 17.5 " underarm to underarm. Tag is marked s/p. Please note the measurements. Small or small petite, judge by the inches. Pretty mint green and white pattern.