Whether we're working into shape with some early season laps or feeling our best on a mid-season tour, the Swix RaceX Classic 1/2-Zip Top keeps us moving in the mountains. The soft synthetic material is highly stretchy, so the baselayer stays close to our body no matter how hard we're working. The breathable fabric and half-zip collar keep us cool as we work up a sweat, and the fabric dries quickly to keep us from getting cold while we wait for the lift.