The Kari Traa Rachel Half Zip is a baselayer top that pairs merino wool with Tencel lyocell and stretchy elastane. Mesh panels at the underarm raglans and upper back add airflow, while contrast fabric sits at the collar and forearms for added flexibility and warmth. What Our Gearhead(R) Experts Are Saying:"I stop at the top of a climb, and the shirt is already drying by the time I zip up for the descent. The Tencel in the blend does that, so I'm not riding down in a damp layer."