The Kari Traa Butterfly Half-Zip is an award-winning women’s synthetic performance pullover for hard training. Whether you wear it as a baselayer or on its own, the super-soft, breathable fabric quickly wicks away moisture when you work it. The slim fit and flatlock seams keep it comfy, while the stretch material moves with you. Extra-long cuffs and a ribbed hem stop it riding up. And it still rocks the subtle signature pattern.